Answer:
51.33 cm
Explanation:
Step 1: Check what is given and asked to find out. In this problem we are provided with the radius 21 cm and the angle at center of the circle is 140°.
→ radius (r) = 21 cm and angle (Ø) = 140°
To find: length of arc (l).
Step 2: Do the calculations. But before that we need to know that which formula we are going to use to do the calculations.
Formula: l = 2πr Ø/360°
Let's dive in!
→ l = 2 × 22/7 × 21 × 140°/360°
→ l = 44 × 3 × 7/18
→ l = 924/18
→ l = 51.33
Hence, the length of the arc is 51.33 cm.