In the given figure the boundary of the shaded region consists of four semi-circular arcs, the smallest two being equal. If the diameter of the largest is 14 cm and of the smallest is 3.5 cm, find

i) length of the boundary ii) Area of the shaded region

Given: AB = 14 cm

Radius d₁ = d₂ = 3.5 cm

Radius D = 7 cm

To find: Area of shaded region.

Explanation:

Mark the semicircles as:

Length of the boundary = Length of Semicircle 1 + Length of Semicircle 2 + Length of Semicircle 3 + Length of Semicircle 4

= 44 cm

Area of the shaded region = Area of region 1 + Area of region 4 – (Area of region 2 + Area of region 3)

= 86.625 cm²