There are two concentric circles of different radius. A chord of bigger circle is tangent to smaller circle if the length

There are two concentric circles of different radius. A chord of bigger circle is tangent to smaller circle if the length of tangent is 14 units, find the area enclosed between two circles?

a)            49 sq. units

b)            154 sq. units

c)            63 sq. units

d)            308 sq. units

Sol:

R² – r² = 49

Enclosed area = = π (R² – r²)