Question

A running track has 2 semicircular ends of radius 63m and two straight lengths.the perimeter of the track is 1000m.find each straight length

Answer 1

radius of two semicircular ends
                  r = 63 m
Perimeter of 1 semicircular end = pi * r
perimeter of 2 semicircular ends = 2 pi * r
                                                    = 2 * pi * 63
                                                     = 396 m
Let the length of track be l

 so length of two tracks = 2 l
Thus 

total perimeter of the track = 2l + 396
                         1000 = 2l + 396
                               2l = 604
                                l = 302 m
Thus each straight length is equal to 302 m

Answer 2

Solution :-

Radius = 63 m

Two semi circles = 1 full circle

Perimeter or circumference = 2πr

⇒ 2*22/7*63

⇒ 2772/7

Circumference = 396 m

Now,

'x' be the length of the straight length.

So, total perimeter = 2x + 396 

It is given that total perimeter is 1000 m.

⇒ 2x + 396 = 1000

⇒ 2x = 1000 - 396

⇒ 2x = 604 

⇒ x = 604/2

⇒ x = 302 m

So, length of each straight length is 302 m

Answer.