Question

In the diagram, CA is tangent to circle P. The e

radius of circle P is 8 cm and BC = 9 cm. What
is AC?

Answer 1

Radius hits any tangent at 90°

So

• AC²=PC²-AP²
• AC²=(9+8)²-8²
• AC²=17²-8²
• AC²=289-64
• AC²=225
• AC=15cm

Answer 2

C. 15 cm

Step-by-step explanation:

The radius is the same in a circle. PA and PB has same length of 8 cm.

In order to find AC, find the length of PA and PC.

Here given:

• PA = 8 cm

• PC = PB + BC = 8 cm + 9 cm = 17 cm

Hence solve using Pythagoras theorem:

• a² + b² = c²

• AC² + PA² = PC²

• AC² + 8² = 17²

• AC² = 289 - 64

• AC = √225

• AC = 15