The surface area of a straight triangular prism is determined by the length of its side edge is 5cm, the bottom is a right triangle, the length of its right side is 4cm, and the length of its hypotenuse is 5cm The top and bottom are right triangles

The surface area of a straight triangular prism is determined by the length of its side edge is 5cm, the bottom is a right triangle, the length of its right side is 4cm, and the length of its hypotenuse is 5cm The top and bottom are right triangles

According to the known conditions and Pythagorean theorem, if the other right side is 3cm, the sum of the area of the upper and lower triangles is 3 × 4 = 12 square centimeters
The side is 3 × 5 = 15 square cm, 4 × 5 = 20 square cm, 5 × 5 = 25 square cm, 12 + 15 + 20 + 25 = 72 square cm
The surface area of this straight prism is 72 square centimeters
According to known conditions and Pythagorean theorem, another right angle side is 3cm, then
The surface area of straight prism is 3 * 4 / 2 * 2 + (3 + 4 + 5) * 5 = 72 cm2
Two practical problems of grade five in primary school
1. In a basket of fruits, the number of oranges accounts for 1 / 4 of the total number, the number of pears is 3 / 5 of the number of oranges, and the rest are 24 apples. How many oranges are there?
2. The school bought two football and five volleyball, a total of 220 yuan, the price of each volleyball is 1 / 3 of the price of football, how much is each football and volleyball?
1. The proportion of pears in the total: 1 / 4 × 3 / 5 = 3 / 20
Total number = 24 (1-1 / 4-3 / 20) = 40
Orange = 40 × 1 / 4 = 10
2. The price of each volleyball is 1 / 3 of the price of football, 5 is 1 / 3 × 5 = 5 / 3
Each football: 220 ÷ (2 + 5 / 3) = 60 yuan
Each Volleyball: 60 × 1 / 3 = 20 yuan
The relation and difference between speed and speed
RT
What are their formulas and what are their connections and differences?
The main answer is the difference
Velocity is a vector with direction and size, and its formula (definition) is: velocity = displacement / time;
Namely
>
v=s/t
Note: - > the symbol represents vector and is marked on letter. (the standard writing method of vector calculation must have the symbol -)
Speed is a scalar, and its formula (definition) is: speed = distance / time
That is v = s / T
In fact, the speed of learning in junior high school is equivalent to that in senior high school
Speed is a vector with direction and size, and its formula (definition) is: speed = displacement / time; speed has only size and is a scalar, and its formula (definition) is: speed = distance / time. In fact, the "speed" of learning in junior high school is equivalent to the "speed" of learning in senior high school.
Speed is the combination of size and direction. Belongs to vector
The rate is scalar and has only size
Speed is distance divided by time, and speed is displacement divided by time. Distance and displacement are different. Displacement is the distance between two particles, the distance from the end point to the starting point. I'll tell you the difference between distance and displacement. Do you think taxis are charged by distance or displacement? If charge by displacement, then I come out from home, take a bus, go to a trip back, displacement is 0, ha ha, don't pay
Speed is distance divided by time, and speed is displacement divided by time. Distance and displacement are different. Displacement is the distance between two particles, the distance from the end point to the starting point. I'll tell you the difference between distance and displacement. Do you think taxis are charged by distance or displacement? If charge by displacement, then I come out from home, take a bus, go back, displacement is 0, ha ha, don't pay, put away
If the base of a straight triangular prism is an isosceles right triangle with a 4 cm hypotenuse and a 5 cm side edge, its volume is
20 square centimeters
Prism volume = bottom area * height = (1 / 2) * (2 times the square of radical 2) * 5cm (height) = 20cm
It takes 40 days for team a to build a section of highway, while it takes 24 days for team B to build a section of highway. Now the two teams start from both ends at the same time, and they meet at 750 meters away from the midpoint. How long is this section of highway?
The two teams need to repair together: 1 △ 140 + 124, = 1 △ 115, = 15 (days); the length of this section of highway: 1500 △ 124 × 15-140 × 15, = 1500 △ 58 − 38, = 1500 △ 14, = 1500 × 4, = 6000 (meters); a: the length of this section of highway is 6000 meters
What is the relationship between average velocity and average velocity?
1、 In this case, it is the unit of velocity in the first and the last time points of the curve
The former is the average value of displacement to time, and the latter is the average value of distance to time
Velocity is a vector, it has size and direction. And rate is scalar, only size, no direction...
Formula of side area of straight triangular prism
Let the height of a straight triangular prism be h, and the lengths of the two vertical sides of a right triangle with cross section be a and B respectively
Then the side area is equal to the perimeter of the triangle C = [a + B + root sign (square of a + square of B)], and the side area is c * H
A practical problem of mathematics in grade five of primary school
There is a pile of stones. The first time we used 15 tons, the rest is as much as we used. How many tons did this pile of stones have?
The rest is as much as used, which means half used, half of the total
So it's a formula
Let the total amount be X
1/2x=15
X = 30 tons. So it's 30 tons
You can also think, use the rest as much as use, so the rest is 15 tons
The total amount is equal to the rest, 15 + 15 = 30 tons
What is the relationship between velocity and instantaneous velocity
Therefore, instantaneous velocity refers to the velocity of an object at a certain time, which can accurately describe the real velocity of an object at a certain time, and its size is equal to the velocity at that time
Speed is a vague concept, which means more to the average value. For example, the speed of an aircraft is 800 km / h, which means that the average speed of an aircraft in an hour is 800 km / h. It can not accurately describe the real speed of an aircraft in a moment. In fact, we do not need to know the speed of an aircraft in every instant in the sky
But the instantaneous speed is often encountered in some places, such as tennis games, there are special equipment in the court to measure the speed of the ball issued by the athletes, that is the instantaneous speed. Also, when doing collision tests, we need to know exactly how much the instantaneous speed is when two objects collide
See?
Velocity is a vector. It has magnitude and direction. The rate is an undirected scalar. Instantaneous rate is the average rate in a short time.
Speed refers to the speed and direction of an object's motion.
Instantaneous speed refers to the instantaneous speed of an object. There is no direction.
There is no relationship between them.
Even if the values are equal, that's not the rule.
The average speed is the ratio of distance to time, only the size, no direction.
The average velocity is the ratio of displacement to time, which has both size and direction. The size is the ratio of the length of the line with the initial position pointing to the end position to the time, and the direction is from the initial position to the end position.
Speed is the speed of an object's motion, or the rate of change equivalent to the distance.
Instantaneous velocity is the velocity of an object passing through a certain position or at a certain moment.
Whether the speed is average speed or instantaneous speed depends on the meaning of the question. ... unfold
The average speed is the ratio of distance to time, only the size, no direction.
The average velocity is the ratio of displacement to time, which has both size and direction. The size is the ratio of the length of the line with the initial position pointing to the end position to the time, and the direction is from the initial position to the end position.
Speed is the speed of an object's motion, or the rate of change equivalent to the distance.
Instantaneous velocity is the velocity of an object passing through a certain position or at a certain moment.
Whether the speed is average speed or instantaneous speed depends on the meaning of the question. Put it away
A formula for calculating the volume of a triangular prism given its side area
Let the volume of the triangular prism abc-a1b1c1 be V, P and Q be the points on the side edges Aa1 and CC1 respectively, and PA = qc1, then the volume of the pyramid b-apqc is (V / 3)
Let the distance from B to plane AC1 be h, and the area of parallelogram a1acc1 be s
The volume of triangular prism abc-a1b1c1 is v = SH / 2
PA = qc1, APQC area = a1acc1 area / 2 = s / 2
The volume of pyramid b-apqc = (s / 2) H / 3 = SH / 6 = V / 3
Why is the volume of triangular prism abc-a1b1c1 v = SH / 2
Divide by 2. Isn't the volume of the prism base set times the height
If you are decisive, you need to type out the whole problem, and then we can solve it for you. Mathematics needs to analyze the specific problems. Different conditions are given, and different solutions are given. The conditions you give now are too limited. There is not even a graph. Sometimes the auxiliary line is used to solve the problem. It is very important to find the "height" by calculating the volume, And then there's the area of the base, which needs to be solved separately. You can see that v = 1.3 s h can be obtained from the ordinary formula of prism volume
V=1/3SH
Let the distance from B to plane AC1 be h, and the area of parallelogram a1acc1 be s
Then the volume of triangular prism abc-a1b1c1 is v = SH / 2
Because at this time, v = bottom area × height is not the volume of a triangular prism, but the volume of a hexahedron (similar to a cuboid) with a1b1c1 as the bottom, so it needs to be divided by 2.
Do you understand that? If you don't understand, you can help me. ... unfold
Let the distance from B to plane AC1 be h, and the area of parallelogram a1acc1 be s
Then the volume of triangular prism abc-a1b1c1 is v = SH / 2
Because at this time, v = bottom area × height is not the volume of a triangular prism, but the volume of a hexahedron (similar to a cuboid) with a1b1c1 as the bottom, so it needs to be divided by 2.
Do you understand that? If you don't understand, you can help me. Put it away
You must type out the whole question so that we can give you an answer. Mathematics is a matter of concrete analysis. Different conditions give different solutions. The conditions you offer are too limited. Not even a picture. Sometimes you have to use auxiliary lines to solve problems. It's very important to find the volume and the height, and the bottom area. We have to work it out separately. If you look at the ordinary prism volume formula, you can see that v = 1 / 3 s h... expansion
You must type out the whole question so that we can give you an answer. Mathematics is a matter of concrete analysis. Different conditions give different solutions. The conditions you offer are too limited. Not even a picture. Sometimes you have to use auxiliary lines to solve problems. It's very important to find the volume and the height, and the bottom area. We have to work it out separately. If you look at the ordinary prism volume formula, you can see that v = 1.3 s h  is folded