If the base of an isosceles right triangle is 5cm long, its area is By the way, which is the bottom of an isosceles triangle and which is the bottom of an RT triangle

If the base of an isosceles right triangle is 5cm long, its area is By the way, which is the bottom of an isosceles triangle and which is the bottom of an RT triangle

According to the Pythagorean theorem, the waist length is equal to 5 / 2 of the root, so the area is equal to 1 / 2 of the waist length x the waist length is equal to 25 / 4
Which is the bottom of an isosceles triangle, and which is the bottom of an RT triangle
An isosceles triangle is equal. Two sides are the waist and the third is the bottom
The bottom edge of RT triangle can be any edge

As shown in the figure, the mass of the shell of the spring scale is m, the mass of the spring and the hook is ignored, and a heavy object is hung on the hook. Now, a vertical external force is used to pull the spring scale. When the spring scale moves upward in a uniform and straight line, the indication is F1; if the spring scale moves upward in a uniform and straight line with acceleration a, the indication of the spring scale is (gravity acceleration is g) ()
A. mgB. F1+mgC. F1+maD. （1+ag）F1

Let the mass of the object be M0. When the spring scale moves upward in a straight line with uniform speed, the indication is F1, F1 = m0g. When the spring scale moves upward in a straight line with uniform speed with acceleration a, according to Newton's second law, f2-m0g = m0a, the solution is F2 = (1 + Ag) F1. So D is correct, a, B, C are wrong, so D is selected

There are four sixth grade math problems for the next semester
1. The bottom area of a cylinder is 3.14 square centimeter. If the bottom is unchanged and the height is increased by 2 cm, its side area is 43.96 square centimeter. What is the original volume of the cylinder?
2. A cylindrical glass tank with a volume of 628 liters. If a quarter of water is injected into the tank and the water is 30 cm away from the tank mouth, the bottom area of the tank can be calculated
3. A cube with an edge length of 40 cm has a round hole with a diameter of 4 cm at the top and bottom, and the hole is 10 cm deep
First question: what's the surface area of this solid figure?
Second question: what is the volume of this solid figure?
If you answer well, I'll add more!
Urgent, give the answer before eight o'clock!
Add a formula before the formula.
thank you!!!!!!!!!!
And the formula has to be worked out step by step.
thank you!!!!!!!!!!!!!!!!

1
The bottom area of a cylinder is 3.14 square centimeters
According to the area formula of the circle, the radius of the circle can be calculated as 1 cm
Circumference of circle = 2 * 3.14 = 6.28
Side area = perimeter x height
Then the height increased by 2 cm = 43.96 / 6.28 = 7 cm
Original height = 7-2 = 5cm
Volume = bottom area x height = 3.14 * 5 = 15.7 cm3
two
628000 * (3 / 4) divided by 0.3 is equal to 15700 (square centimeter)
three
(1) Surface area the surface area is the area of a cube minus the area of two circles
40 * 40 * 6 = 9600 (cm2)
4 * 3.14 * 10 * 2 = 251.2 (cm2)
9600 + 251.2 = 9851.2 (cm2)
(2) The volume is the volume of a cube minus the volume of a cylinder
Square of 40 * 40 * 40-2 * π * 2 * 10 = 9600-40 π = 63748.8 (CC)

One person uses 100N horizontal pulling force to pull the trolley forward 10m on the horizontal plane. If the trolley weighs 400N, the work done by the pulling force is______ J. The work done by gravity is______ J．

The work done by pulling force: w = FS = 100N × 10m = 1000j. The car moves in the horizontal direction without moving distance in the gravity direction, and the work done by gravity is 0j. So the answer is: 1000; 0

In the arithmetic sequence [an], S6 = S13, and A1 > 0, then the largest term in the sequence [Sn] is

S13-S6=a7+a8+…… +a13=(a7+a13)*7/2=7a10
So A10 = 0
And A10 = a1 + 9D
So d = - A1 / 9

The elevator in the mine starts to rise at a constant speed from a standstill, and then rises at a constant speed of 20 m after reaching a speed of 4 m / s in 5 s,
Then decelerate and rise, stop at the wellhead after 4S, and calculate the depth of the mine

Acceleration part:
The average velocity is 4 + 0 divided by 2 = 2m / s
So the displacement is 2 × 5 = 10m
Uniform velocity part
20m
Deceleration part:
The average velocity is 4 + 0 divided by 2 = 2m / s
So the displacement is 2 × 4 = 8m
So the depth of the mine: 10 + 20 + 8 = 38m

If a and B are rational numbers, then a * b = 3a-2b, and Xiao Ming calculates 2 * 5 = - 4, then 3 * (- 6) =?
emergency

3*（-6）= 3×3 - 2×（-6）=21

Given that the solution of the equation x + 12-kx + 13 = 1 is x = - 5, find the value of K

The solution of X + 12-kx + 13 = 1 is x = - 5, − 5 + 12 − K + 13 = 1, - 12-2 (- K + 1) = 6 and K = 10

There are two points A. B on the number axis. The distance between a and B is 1. The distance between a and the origin is 3?

Then a may be positive or negative 3. When positive 3, B is 2 or 4. When a = - 3, B is - 2 or - 4, so the distance from B to the origin is 2 or 4

Chengnan gas station needs to build a new oil tank. It is planned that the oil tank can store 200 tons of diesel oil. Now take 50 ml of this diesel oil as a sample, and measure the mass of the sample with a balance to be 40 G?

200*1000*1000/40=5*10^6,5*10^6*50=2.5*10^8ml=250m^3