what's the answer to this sum? please help, i have to submit it tomorrow?

Question

http://img277.imageshack.us/img277/3528/sumnm0.jpg


^^ can someone please work this sum out and tell me the answer with the working?

please post the working too

the area of the square is 98cm²
and the area of the shaded area is 14cm²

but i need the working =(

Answer 1

Look at the square. Draw two lines along the diameters (the diagonals of the square) to make 4 equal triangles. Each will have sides equal to 7cm. The area of one triangle with legs of 7cm and 7cm is 1/2 (b*h) = 7*7 / 2 = 24.5 sq. cm. Since you have 4 triangles like this, that is 98 sq. cm.

Next the area of the full circle is given by the formula A = pi * r^2. That works out to 49 pi or 153.93804 sq. cm.

Subtract the two and you have 55.93804 sq. cm, but the shaded area is only 1/4 of the area outside the square.

55.93804 / 4 = 13.98451 sq. cm.

So the square is 98 sq. cm., the shaded area is about 14 sq. cm.

Answer 2

Ok.
The area of the square will be the radius (7)multiplied by 2, then squared, then divided by 2, (98).

The area of the circle is r squared * pi. I want to find 1/4 of the area, then subtract 1/4 of the area of the square from it.

49pi/4 is 1/4 of the area of the circle
98/4 is the area of 1/4 of the square

so the shaded region is (49pi - 98)/4, or about 14

make sure the answer is in the proper format, good luck.