Question

An athletic track 14 m wide consists of two straight sections 120 m long
joining semi-circular ends whose inner radius is 35 m. Calculate the area of
the shaded region.
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Answer 1

Answer:

l = 120m, b = 14m, r1 = 35m, r2 = 49m

area of 2 straight sections = 2*l*b = 2*120*14 = 3360m²

area of 2 semicircular ends = 2[(½πr2²)-(½πr1²)]

= 2*½*22/7*(49²-35²)

= 22(2401-1225)/7

= 22*1176/7

= 22*168

= 3696

total area = 3696+3360 = 7056m²