Question

A sector of 100 degree cut off from a circle contains 70.65 cm square. Find the radius of the circle

Answer 1

area of sector= °/360° ×πrr

70.65=100/360×22/7×r×r
(70.65×36×7)/10×22=r×r
r×r=80.92
approximately 81
r×r=81

therefore r=9cm

Answer 2

Answer:

9cm

Step-by-step explanation:

Sector angle (θ) = 100°

Area of a  Sector of a circle = 70.65 cm²

Area of sector =  (θ /360) ×πr²

70.65 = (100/360 ) × 3.14 × r²

70.65 =( 5/18) × 3.14 × r²

70.65 × 18  = 5 × 3.14 × r²

r² = (70.65 × 18) / (5×3.14)

r² = (70.65 × 18) / 15.7

r² = 4.5 × 18 = 81

r² = 81

r =√81 = √9 × 9 = 9

Hence, the Radius of the circle is 9 cm.

HOPE THIS WILL HELP YOU..