The area of the shaded region is ______________ .
C
Step-by-Step Solution
Insight: The quadrilateral PQRO is a kite with perpendicular diagonals, making its area simply half the product of the diagonals.
Exam route:
- By the Central Angle Theorem, .
- is a right isosceles triangle with legs . Thus, hypotenuse .
- Since and , the line is the perpendicular bisector of .
- The area of quadrilateral is .
- is a radius, so .
- Area = .
Learning route:
- Identify the given: Circle with center , radius . Points on circle. , .
- By the Central Angle Theorem, the angle subtended by arc at the center is .
- In , (radii) and . By Pythagoras, .
- The quadrilateral is a kite because adjacent sides are equal (, and is given).
- A key property of a kite is that its diagonals are perpendicular. Thus, .
- The area of any quadrilateral with perpendicular diagonals is .
- Here, , and (since is on the circle, is a radius).
- Area = .