In the given figure PQRS is a rectangle, whose area is 8 cm $\times$ 4 cm. Triangles are equilateral and the radii of each circle is 1 cm. Then the perimeter of ABCDEFGHIJKLMNA is:
47.84 cm
38.84 cm
36.84 cm
34.84 cm
Solution
The perimeter of ABCDEFGHIJKLMNA
$=$ AB + BCD + DE + EF + FGH + HI + IJK + KL + LM + MNA
$= (8 - 1 - 1) + \dfrac{3}{4}(2\pi .1) + (2 + 2) + \dfrac{3}{4}(2\pi .1) + (8 - 1 - 1) + \dfrac{3}{4}(2\pi .1) + (2 + 2) + \dfrac{3}{4}(2 \pi .1)$
$= 2(8 - 1 - 1) + 4.\dfrac{3}{4}(2\pi .1) + 2(2 + 2)$
$= 12 + 18.84 + 8 = 38.84$ cm