SAT Math

Category - Geometry and Measurement

What is the area of the circle in the figure below?
  1. (169π)/4
  2. (169π)/2
  3. 169π
  4. (13π)/2
  5. 13π
Explanation
Answer: A - The area of the circle is 169π/4. The radius of the circle is equal to half of the diagonal AD. Find AD using the Pythagorean Theorem.

AD2 = AC2 + CD2 = 122+52 = 144+25 = 169
AD=√169=13
r = AD/2 = 13/2
A = r2 π = (13/2)2 π= 169π/4
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