#### Question

Areas of some circles are given below find their diameters.

(1) 176 sq cm

(2) 394.24 sq cm

(3) 12474 sq cm

#### Solution

(1) 176 sq cm

Ar = πr²

⇒ 176 = `22/7 xx` r²

⇒ r² = `(176 xx 7)/22` = 56

⇒ r = `sqrt[56]`\

d = 2r = 2`sqrt[56]`

(2) 394.24 sq cm

Ar = πr²

⇒ 394.24 = `22/7 xx` r²

⇒ r² = `(394.24 xx 7)/22` = 125.44

⇒ r = 11.2

d = 2r = 2 x 11.2 = 22.4 cm

(3) 12474 sq cm

Ar = πr²

⇒ 12474 = `22/7 xx` r²

⇒ r² = `(12474 xx 7)/22` = 3969

⇒ r = 63

d = 2r = 2 x 63 = 126 cm

Is there an error in this question or solution?

Solution Areas of Some Circles Are Given Below Find Their Diameters. Concept: Perimeter and Area of a Circle.