Question

Question is attached

Answer 1

it is not.

Answer 2

Firstly, do you know the formula, which helps you to find an area of a full circle?

Answer 3

pi*r^2?

Answer 4

yes, you are right, it is \[A=\pi r ^{2}\] so if Area of a full square is \[A=\pi r ^{2}\], then area of QUARTER of square is \[A=\frac{ \pi r ^{2} }{ 4 }\] - that's is because quarter of circle is 4 times smaller than a full circle. Do you agree with me? If yes, I can try to explain more.

Answer 5

Yes I agree

Answer 6

So, let's move on.

Do you agree that area of a bolden (or shaden, how it is written in the book) can be found:
\[A _{AEDB}=A _{AEC}-A _{BDC}\] - from full quarter you need to subtract the smaller part. Is that right?

Answer 7

That seems to be right

Answer 8

great!

So, firstly you need to find area of AEC, right?

If you need to do it, you need to have a radius,right? Any ideas how to find it? (don't forget, you have the length of AB and the length of AC, which gives you a diameter of a bigger quarter of a circle)

Answer 9

is the radius 8?

Answer 10

yes! now find the area of AEC, because you know the formula

Answer 11

how do you find the area? the two sides are equal to 8?

Answer 12

ah, I have made a mistake. radius of AEC is 4, not 8, because you have forgotten to divide by 2, because radius is 2 times smaller than a diameter
no, use the formula:

\[A _{AEC}=\frac{ r ^{2}\pi }{ 4 }\] you know, that r=4, what answer do youu get?

Answer 13

4pi