Ask your own question, for FREE!
Mathematics 8 Online
OpenStudy (anonymous):

1. In the diagram below, line segment AT is a diameter of the circle with center O. What is the area of the shaded part of the circle? Show your work or provide an explanation for your answer.

OpenStudy (anonymous):

OpenStudy (anonymous):

can someone help me?

OpenStudy (notamathgenius):

I'm not really good with this stuff sorry D:

OpenStudy (anonymous):

its okay..

OpenStudy (anonymous):

@touseii45

OpenStudy (anonymous):

okay well you want to find the area of the circle first

OpenStudy (anonymous):

so do you know your formula?

OpenStudy (anonymous):

the area is 201.1

OpenStudy (anonymous):

OK, first find the area of the circle, which is \[\pi \times r ^{2}\] and r is half of the diameter Next find the area of the triangle. To do that, calculate the base and the height, using the fact that u know the hypothenuse and the angle 30. Than use the formula : area of a triangle=0.5xheightxbase

OpenStudy (anonymous):

now youve lost me :(

OpenStudy (anonymous):

what he means is 3.14 (which is pi) times r squared (or half of the diameter times itself)

OpenStudy (anonymous):

i know the area of the circle

OpenStudy (anonymous):

if your diameter is 16 divide that by 2

OpenStudy (anonymous):

what is it?

OpenStudy (anonymous):

the area is 201.1

OpenStudy (anonymous):

correct now do you have the area of the triangle?

OpenStudy (anonymous):

no, i cant figure out how..

OpenStudy (anonymous):

ok, do u know that sinx=opposite/hypothenuse ?

OpenStudy (anonymous):

and that cosx=adjacent/hypothenuse? u can use these two facts to find the base and the height of the triangle

OpenStudy (anonymous):

im sorry thanks for your help, but im more confused than before i cane here

OpenStudy (anonymous):

im confused too

OpenStudy (anonymous):

did u learn about sine and cosine? If u haven't, than I don't see how u could solve this question

OpenStudy (anonymous):

yes.

OpenStudy (anonymous):

alittle

OpenStudy (anonymous):

so what exactly do i do to find the area of the triangle

OpenStudy (anonymous):

OK, so \[\sin (of an \angle)=\frac{side opposite \to \angle }{ hypothenuse (the longest side of the \triangle }\]

OpenStudy (anonymous):

and \[\cos x=\frac{ adjacent }{ hypothenuse }\]

OpenStudy (anonymous):

but which fdo i do?

OpenStudy (anonymous):

you throwing formulas at me is just confusing me

OpenStudy (anonymous):

therefore, to find the base of the triangle, we calculate: \[\sin(30)=\frac{ base }{ 16 }\] and to find the height of the triangle, we calculate: \[\cos (30)=\frac{ height }{ 16 }\]

OpenStudy (anonymous):

I'm sorry, I'm not trying to confuse, I'm just working through the problem with u

OpenStudy (anonymous):

oohhhh okay!!1

OpenStudy (anonymous):

we got it?

OpenStudy (anonymous):

:D

OpenStudy (anonymous):

but how do i solve them?

OpenStudy (anonymous):

well, \[the base=16\sin 30\] \[the height=16\cos 30\]

OpenStudy (anonymous):

so? 8 and 13.86

OpenStudy (anonymous):

ok, now we plug that into the triangle fornmula (which is half times base times height) And then we subtract the area of the triangle from that of the circle

OpenStudy (anonymous):

55.44 and 201.1-5544=145.66 os that right?

OpenStudy (anonymous):

55.44***

OpenStudy (anonymous):

:D well done! that's what i got, anyways

OpenStudy (anonymous):

so final answer=145.636304

OpenStudy (anonymous):

:)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!