Question

The area of sector AOB is 20.25(pi)ft^2 . Find the exact area of the shaded region. helpp :/

Answer 1

you subtract the area of the sector from the area of the triangle to get the shaded area

Answer 2

but how do i figure out the area of the triangle , sorry . i'm horrible in geometry

Answer 3

its fine,

area of triangle

Area = (base*height)/2

A = (bh)/2

A = (9*9)/2

A = 81/2

A = 40.5

Answer 4

okay, so when i subtracted 9.85 from 40.5 i got 30.65

and my answer choices are

A. 20.25(pi)-40.5ft^2
B. 20.25(pi)-81ft^2
C.20.25(pi)-40.5(square root)2ft^2
D. None of these

so now just test each answer choice i guess?

Answer 5

\[C. 20.25\pi-40.5\sqrt{2}ft ^{2}\]

Answer 6

it would be 20.25(pi)-40.5ft^2 because you just leave 20.25pi alone

you can evaluate it, but they chose to leave it to get the most exact answer possible (with decimals)

Answer 7

Area of Shaded Region = (Area of Sector) - (Area of triangle)

Area of Shaded Region = (20.25pi) - (40.5)

Area of Shaded Region = 20.25pi - 40.5

which is choice A

Answer 8

C is close, but it has a square root in it, which isn't the case here

Answer 9

thanks again, ! your extremely helpful!

Answer 10

yw