Question

calculate the area of a circular ring, whose internal and external radii are 3cm and 10 cm respectively

Answer 1

answer

286 cm square

explanations

let external radius R = 10 cm

internal radius r = 3 cm

now

area of a circular ring = area of circle with radius R - area of circle with radius r

=22/7 (10 square) -22/7 (3 square) cm square

=22/7 (100-9) cm square

=22/6 (91) cm square

=22×13 cm square

=286 cm square