Question

-Calculate the area of the sector bounded by DQ,EQ, AND (ARC) DE
- Approximate the area of the circle segment bounded by LINE DE and(ARC) DE .
(Use trigonometry as needed.)

Answer 1

first problem...

area=R^2/5=pi*15^2/5=45*pi.
area of the triangle....(1/2)DQ*EQsin(72)=(1/2)*225sin72 =107
so the area of the line DE and ARC is 45 pi- 107=34.37

Answer 2

if u don't understand then let me know...

Answer 3

for a total circle the angle formed in centre is 360( or 2 pi);
for 360 angle the area is piR^2
so 72 ..........................piR^2*72/360=pi*R^2/5