The diameter of a round flower bed is 8m. How many meters is the perimeter of the flower bed and how many square meters does it cover

The diameter of a round flower bed is 8m. How many meters is the perimeter of the flower bed and how many square meters does it cover

Radius = 8 △ 2 = 4m
Perimeter = 8 × 3.14 = 25.12m
Area = 4 × 4 × 3.14 = 50.24 square meters

There is a round flower bed with a circumference of 125.6 meters on campus. What is the floor area of this flower bed?

2, = 3.14 × 202, = 3.14 × 400, = 1256 square meters. A: the floor area of this flower bed is 1256 square meters

The perimeter of a round flower bed in the square garden is 18.84 meters. How many square meters does the flower bed cover
Determinant

Find out the diameter of the flower bed first
Formula: perimeter divided by 3.14 (PI)
That is 18.84 / 3.14 = 6
From the diameter, the radius is 6 / 2 = 3
The area formula of a circle is: S = 3.14 x r squared
So the area of the flower bed is
3.14x3 square
=3.14X9
=28.26 square meters

What kind of figure can you spell out with four identical isosceles right triangles? And draw the figure

Rectangle, square

Divide an isosceles triangle into two right triangles

Make a bottom vertical bisector

It is known to make a right triangle with a straight angle and a hypotenuse

Make ∠ mcn90 & # 186;
On the ray cm, cut CA equal to the known right angle side length, take a as the center of the circle, take the oblique side length as the radius to make the arc intersection ray CN at B
Then ⊿ ABC is the triangle

Given the length of a right side and the hypotenuse of a right triangle, we can find the height of the hypotenuse
It is known that one right side of a right triangle is 6, and the length of the hypotenuse is 9

Pythagorean theorem:
Let the height of the hypotenuse be X
Square of X + 36 = 81
(36 is the square of 6, 81 is the square of 9)
Square of x = 45
Radical five = 2.2360679774998
2.2360679774998 ×3=6.7...

How to draw a graph with ruler and gauge to make an angle equal to a known angle

Known: ∠ AOB,
Find: ∠ a'o'b ', so that: ∠ a'o'b' = ∠ AOB,
Method:
1. Make any ray OA ',
2. Take the point o as the center of the circle and the appropriate length as the radius to make the arc intersection OA and ob at the points m and n,
3. Take the point o 'as the center and the same length as the radius to make the arc intersection o'b' at the point P,
4. Take point P as the center of the circle, take Mn as the radius, and make the arc intersection at point a ',
5. Passing through point a 'as ray o'a'
A'o'b 'is the required value

Drawing with ruler: draw an angle equal to the known angle

Known: ∠ AOB,
Calculate: ∠ CDE so that: ∠ CDE = ∠ AOB,
Method:
1. Make any ray De,
2. Take the point o as the center of the circle and the appropriate length as the radius to make the arc intersection OA and ob at the points m and n,
3. Take point D as the center and the same length as the radius to make arc intersection de at point P,
4. Take point P as the center of the circle, take Mn as the radius, and make the arc at point C,
5. Pass through point C as ray DC
The CDE is the required value

Draw a picture with a ruler to make 2 times of a known angle
Given the angle α, the ball is twice her angle
Drawing late

(let the vertex of the corner be o) take a point a on the common edge of the two corners to make the vertical line on the other side, intersect at point P, take a as the center of the circle, AP as the diameter, make the circle, and then make the tangent om of the circle through point O, with the angle mop and two times