2、2/3 ×360=240

3、π r？ ×72/360= 1004.8 cm？

4. The circumference of a circle = 2π r = 2× 3.14× 30 =188.4, then the area =π r? ×36/ 188.4=540

5. The circumference of a circle = 2 π r = 2× 3.14× 4 = 25.12, then the area =π r? ×5/25. 12= 10

6. Sector area =π r? X θ/360 When R is doubled, the area is four times that of the original.

7. Perimeter =2π r×300/360=3 1.4

Area ==π r? ×300/360=94.2