Question

Find the length of arc AB for each circle.

Answer 1

Answer:

see explanation

Step-by-step explanation:

The length of the arc is calculated as

AB = circumference of circle × fraction of circle

(11)

AB = 2πr × $\frac{90}{360}$

     = 2π × 7 × $\frac{9}{36}$

     = 14π × $\frac{1}{4}$

     = $\frac{7}{2}$ π in

(12)

AB = 2πr × $\frac{135}{360}$ ( r = 20 ÷ 2 = 10 )

      = 2π × 10 × $\frac{3}{8}$

      = 20π × $\frac{3}{8}$

      = $\frac{60}{8}$ π

      = $\frac{15}{2}$ π cm