Question

see the attached screenshot for the question.

Answer 1

Concept of Perimeter: The length of the boundary of a closed figure is known as perimeter.

∴ Perimeter = arc BC + arc EF + AB + AF + CD + DE

Given that,

AB = 10 units (in diagram).

Here, arc BC and arc EF form a circle.

Perimeter of Circle = 2πr

∴ Perimeter = 2πr + AB + AF + CD + DE

⟹ Perimeter = 2π(10) + 10 + 10 + 10 + 10 units

[If we observe, we can find that the rectangle is divided into several closed figures, they are squares! Also, side of the square = radius of circle.]

= 20π + 40 units

∴ (a) 10 + 10 + 10π + 10 + 10 + 10π

and,

(b) 40 + 20π is correct.

@Psyclone