Bluebook SAT Test Circles 5

Question 1

What is the radius of the circle x² + y² − 8x − 6y + 21 = 0?

Accepted Answer

2

Answer

4

Answer

√21

Answer

8

Question 2

A sector of a circle with radius 12 has a central angle of 2π/3 radians. What is its area?

Accepted Answer

48π

Answer

24π

Answer

16π

Answer

96π

Question 3

A chord connects two points on a circle of radius 10, and its perpendicular bisector passes through the center. The midpoint of the chord is 6 units from the center. What is the chord's length?

Accepted Answer

16

Answer

8

Answer

12

Answer

20

Question 4

A circle with center (0,0) passes through the point (−5, 12). What is the area of the circle?

Accepted Answer

169π

Answer

144π

Answer

25π

Answer

13π

Question 5

An angle inscribed in a circle measures 42°. What is the measure of the arc it intercepts?

Accepted Answer

84°

Answer

42°

Answer

21°

Answer

138°

Question 6

A circle has circumference 30π. What is the area of a sector with central angle 120°?

Accepted Answer

75π

Answer

225π/3

Answer

150π

Answer

50π

Question 7

Which of the following equations represents a circle with the largest radius?

Accepted Answer

(x−1)²+(y−1)²=100

Answer

x²+y²=81

Answer

(x+3)²+(y−2)²=49

Answer

(x−5)²+y²=64