1, calculate the area of each of the following circles:

(1) A circle with a radius of two meters

(2) A circle with a diameter of 10 cm.

3.14 * 2 2 =12.56 (square decimeter)

10/2 = 5cm

3.14 * 5 2 = 78.5 (square centimeter)

2. Calculate the area of each circle according to the following conditions.

R= 1 decimeter

D = 20mm

3.14 *12 = 3.14 (square decimeter)

20÷2= 10 (mm)

3.14 *102 = 314 (square millimeter)

C=6.28 meters

6.28÷3. 14÷2= 1 (m)

3.14 *12 = 3.14 (square meter)

The radius of the round plastic sheet is 9 decimeters. How many square decimetres is its area?

3.14 * 9 2 = 254.34 (square decimeter)

The diameter of the round flower bed is 6 meters. What is the area of this flower bed?

6÷2=3 (meters)

3.14 * 3 2 = 28.26 (m2)

5. The bottom of a pot is round, and its circumference is 3. 14m. What is the area of the bottom of this boiler?

3.14 ÷ 3.14 =1(m)

1÷2=0.5 (m)

3. 14 * 0.5 2 = 0.785 (m2)