SOLUTION: Number 58 on the worksheet found at this link! : http://www.phuhs.org/teachers/weaversu/FR1.htm I need to know how to solve it and the answer. Thank you so much!!!!

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Question 755114: Number 58 on the worksheet found at this link! :
http://www.phuhs.org/teachers/weaversu/FR1.htm
I need to know how to solve it and the answer. Thank you so much!!!!
Found 2 solutions by KMST, josgarithmetic:
Answer by KMST(5328) (Show Source):
You can put this solution on YOUR website!
The two dotted lines (OA and OB) and the arc AB form the border of a sector (a piece of pie) with AB as a curved border.
The area of that sector is of the area of the circle, because the measure of arc AB is and that is of the measure of the whole circumference.
The area of a circle is calculated as .
In this case, the area of the circle is square units.
Then, the area of the sector with AB as a curved border is
square units.
Triangle OAB is an isosceles right triangle.
The angle at O is a right angle.
The length of each leg is units.
Taking one leg as the base of the triangle, the other leg would be the height, and the area of triangle OAB is
square units.
The area of the shaded part is the area of sector OAB minus the area of triangle OAB.
It is square units.

Answer by josgarithmetic(39617) (Show Source):
You can put this solution on YOUR website!
The lengths given are enough that you can calculate the area of the combined triangle halves, based on using (1/2)*{base}*{height}. The area of the sector can be calculated easily knowing that the central angle is 90 degrees. You want a difference of two areas. For the sector, the area is a of using 1 as the radius.

Do you recognize what kind of triangle you have there?

That's is as far as this solution is taken because you seem to be taking a test. You have now been given enough informative help.