The area of sector AOB is 20.25pi cm^2 . Find the exact area of the shaded region.

Question

anonymous · Answer

attachment

ganeshie8 · Answer

find Area of triangle AOB and subtract it from sector area

anonymous · Answer

The area of AOB is 20.25.

ganeshie8 · Answer

thats the given sector AOB area.

anonymous · Answer

woops, its 63.585 if you multiply it by pi

ganeshie8 · Answer

Yes. thats the given **sector** area.

ganeshie8 · Answer

we need to remove the triangle area to get area of shaded region

mathstudent55 · Answer

The question asks for the _exact_ area, so just follow what ganeshie8 told you to do. Calculate the area of the triangle and subtract it from 20.25(pi) cm^2.
The answer should look like 20.25pi - _______  cm^2

anonymous · Answer

Do I have to use Sin Cos Tan?

ganeshie8 · Answer

to find the height OA ?

anonymous · Answer

OH. is it 9cm? Because its a radius?

ganeshie8 · Answer

Yes ! very good observation :)

anonymous · Answer

Would it be 20.25pi - 81cm^2?
Because you have to times 9 and 9?

ganeshie8 · Answer

you have to times 9 and 9 and divide it by 2

ganeshie8 · Answer

area of triangle = bh/2

anonymous · Answer

Oh, duhh. 40.5

ganeshie8 · Answer

Yes !