Put a circle into an approximate rectangle. Given that the length of the rectangle is 12.56cm and the width is the radius of the circle, what is the circumference of the circle? Put a circle into an approximate rectangle. Given that the length of the rectangle is 12.56cm and the width is the radius of the circle, what is the area of the circle?

Put a circle into an approximate rectangle. Given that the length of the rectangle is 12.56cm and the width is the radius of the circle, what is the circumference of the circle? Put a circle into an approximate rectangle. Given that the length of the rectangle is 12.56cm and the width is the radius of the circle, what is the area of the circle?

Let the radius of the circle be r
12.56r=3.14r^2
The solution is r = 4
Circumference of circle: 3.14 × 2 × 4 = 25.12cm
Area of circle: 3.14 × 4 × 4 = 50.24 square centimeter

The area of a garden is equal to that of a rectangle. The circumference of a circle is 12.56cm. What is the area of a rectangle?

Radius = 12.56 △ 3.14 △ 2 = 2cm
Area = 2 × 2 × 3.14 = 12.56 square centimeter

The circumference of a circle is 25.7cm. What's the diameter of the semicircle

Because the circumference of a circle is the diameter times 3.14
Then divide 3.14 by 25.7 is the diameter!
The answer is about 8.18cm

In the parallelogram ABCD, if AB = 4cm, BC = 8cm and angle a = 150 °, the area of ABCD =?
5 - 14 days and 23 hours to the end of the problem
In the parallelogram ABCD, ab = 4cm, BC = 8cm, angle a = 150 °, then the area of parallelogram ABCD =?
I want to calculate the process, 16 square centimeters
Please explain how to get it at every step. What's that 4 / 2?

Do parallelogram ABCD, because angle a = 150 degrees, so angle B = 30 degrees
Do AE perpendicular to BC, so AE = half of AB = 2cm. So s = BC * AE = 8cm * 2cm = 16cm square
Do you understand

Point O is the intersection of diagonal lines AC and BD of parallelogram ABCD, and triangle AOB is an equilateral triangle. If the area of this parallelogram is 16, calculate the length of ab

∵ ABCD is a parallelogram, ∵ OA = OC, OB = OD, ∵ Δ AOB is an equilateral triangle, ∵ OA = ob, ′ ABO = 60 °, ∵ AC = BD, ∵ parallelogram ABCD is a rectangle, ∵ bad = 90 °, ∵ ADB = 30 °, ∵ ad = √ 3AB, and s rectangle ABCD = AB * ad = √ 3AB ^ 2 = 16, ∵ AB ^ 2 = 16 / √ 3AB = 4 / (4th root of 3) =

In the parallelogram ABCD, the angle AOB is an equilateral triangle, ab = 4

SΔAOB=1/2*4*2√3=4√3,
So s parallelogram = 4 * s Δ AOB = 16 √ 3
("√" is the root)

If the diagonal of the parallelogram ABCD is an equilateral triangle and ab = 3cm, then the perimeter of the parallelogram is. And the area is

∵ Δ AOB is an equilateral triangle ∵ AB = Ao = Bo ∵ oba = ∵ OAB = 60 ° and ∵ parallelogram ABCD. Compared with the point O ∵ do = Bo ∵ do = Ao ∵ BDA = ∵ DAC ∵ oba = ∵ OAB = 60 ∵ BDA = ∵ DAC = 30 ∵ BDA = 90 ∵ quadrilateral ABCD is a rectangle, ab = 3cm ∵ ad = 3 root, 3cm perimeter is 12

Given that the area of parallelogram ABCD is 4 and O is the intersection of two diagonals, then the area of △ AOB is______ ．

According to the diagonal property of parallelogram, Ao is the middle line of △ abd, so s △ AOD = s △ AOB. Similarly, s △ AOB = s △ BOC = s △ cod, so s △ AOB = 14s parallelogram ABCD = 1

If the area of triangle AOB is 20, then the area of triangle cob is 20
Hope to have a solution

The four triangles divided by the two diagonals of a parallelogram have equal areas
The area of the triangle cob is 20

If the circumference of the bottom surface of the cone is 20 π, the center angle of the fan-shaped circle obtained after the expansion of the side surface is 120 ° and the length of the generatrix is calculated!

The base circumference of a cone is 20 π
Radius = 20 π / π / 2 = 10
∵ the center angle of the fan is 120 ° after the side is expanded
∴120=10×360／l
l=30
Bus length 30