Question

Question 8 (i)
Fig. 12.26 depicts a racing track whose left and right ends are semi-circular.
The distance between the two inner parallel line segments is 60 m and they are each 106 m long. If the track is 10 m wide, find:
(i) The distance around the track along its inner edge

Answer 1

Width of track = 10 m
Distance between two parallel lines = 60 m
Length of parallel tracks = 106 m

DE = CF = 60 m
Radius of inner semicircle, r = OD = O'C
$=\frac{60}{2}m=30m$
Radius of outer semicircle, R = OA = O'B
= 30 + 10 m = 40 m
Also, AB = CD = EF = GH = 106 m
Distance around the track along its inner edge $=CD+EF+2\times \left(Circumferenceofinnersemicircle\right)$
$=106+106+(2\times \pi r)m=212+(2\times \frac{22}{7}\times 30)m=212+\frac{1320}{7}m=\frac{2804}{7}m$