Bluebook SAT Test Circles 8

Question 1

A circle passes through points (0,0), (6,0), and (0,8). What is the radius of the circle?

Accepted Answer

5

Answer

10

Answer

7

Answer

√(100)

Question 2

The equation of a circle is x² + y² − 2x + 4y − 20 = 0. What is the area of this circle?

Accepted Answer

25π

Answer

5π

Answer

20π

Answer

100π

Question 3

A circle has radius r. A sector with central angle 2π/5 is cut out. What fraction of the circle's area does the sector represent?

Accepted Answer

1/5

Answer

2/5

Answer

2π/5

Answer

1/10

Question 4

What is the length of the longest chord of a circle with area 36π?

Accepted Answer

12

Answer

6

Answer

18

Answer

36

Question 5

In a circle, a central angle intercepts an arc of 150°. What is the central angle in radians?

Accepted Answer

5π/6

Answer

5π/12

Answer

3π/5

Answer

7π/6

Question 6

Two circles are concentric (same center). The outer circle has radius 10 and the inner circle has radius 6. What is the area of the ring (annulus) between them?

Accepted Answer

64π

Answer

100π

Answer

36π

Answer

16π

Question 7

A circle has equation (x−3)²+(y+2)²=50. The point (3+t, −2) lies on the circle. What is the positive value of t?

Accepted Answer

5√2

Answer

5

Answer

√50

Answer

10