Question

a circular pond has 90 cm wide footpath along its edge a man walks around the outer edge of the footpath with 66 cm long steps in 400 steps he makes a full round what is the radius of the pond

Answer 1

$outer \: circumference = 400 \times 66 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 26400cm \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 264m \\ 2\pi \times r = 264 \\ r = \frac{132 \times 7}{22} \\ = \: \frac{12 \times 7}{11} \\ = \frac{84}{11} \\ = 7.63$
$763 - 90 = 673cm$