Question

The perimeter of a quadrant of a circle is 75. find its radius

Answer 1

Perimeter of quadrant of circle=2(r) + 1/4×2πr
75=2r+½×22/7r
75=2r+11/7r
75=25r/7
$r = 75 \times \frac{7}{25} \\ r = 7 \times 3 = 21 \: cm$