Question

Laila needs a new bike mirror. Her old mirror was a square with a side length of 7 cm. She wants

the new mirror to have approximately the same area as her old bike mirror.
Which circular bike mirror should Laila buy?
4 cm
7 cm
8 cm

Answer 1

about 4 centimeters

Answer 2

Approximately 4 cm

Explanation:

Old mirror's area = S X S = 7 x 7 = 49cm2

Area of old mirror = Area of new mirror
49 = πr2

49 = 22/7 * r2


`(49 * 7)/(22)` = r2


`(343)/(22)` = r2

15.5909 = r2

r =
`√(15.5909)`
r = 3.948 cm = approx. 4cm

Hope it helps.