Topic 9/10 Review

Find the exact arc length.

Find the exact area of the sector.

In a​ circle, a 90° sector has area 64π in². What is the radius of the​ circle?

• 16 in

• 32 in

• 64 in

• 128 in

• 16 cm

• 8 cm

• 4 cm

• 2 cm

Convert 510^o to Radians

• 25π / 3

• 23π / 8

• 17π / 6

• 51π / 8

Convert 210^o to Radians

• 7π / 6

• 21π / 10

• 5π / 6

• 9π / 4

Find the arc length

• 7 cm

• 28π cm

• 7π cm

• 28 cm

Determine whether a tangent line is shown in the diagram.

• Yes

• No

Is line AB tangent to the circle?

• YES

• NO

• Not enough info

What is the radius of the given circle:
 x²+y²-10x+8y-23=0?

• 4

• 2

• 8