Question

Find the area of a circular ring made by two concentric circles of radii 7cm and 10.50 cm

Answer 1

The area (A) of a circle or circular region is given by A = πr^2, where r is the radius and, by definition, π = circumference/diameter = 22/7 (approximately).

Answer 2

Answer:

Step-by-step explanation:

A= area of bigger circle - area of smaller circle

=π(r+h)  2  −πr  2

 =π(r  2  +h  2  +2hr−r  2  )

=π(h  2 +2hr)

=π(h+2r)h