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A running track has two semi-circular ends with radius 31m and two straights of length 92.7m as shown. Calculate the total area of the track rounded to 1 DP.​

A running track has two semi-circular ends with radius 31m and two straights of length-example-1
User Mohit Bumb
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1 Answer

24 votes
24 votes

Explanation:

the area of a track ? for a track we would normally look for the circumference. the area here is more that of an ice rink.

anyway, the area is the sum of the area of the rectangle in the middle and the areas of the 2 half-circles at both ends. since the half-circles are equally large, they are together the area of the full circle.

the length of the rectangle is 92.7 m.

the width of the rectangle is 2 times the radius (the diameter) of the circle = 2×31 = 62 m

the area of the rectangle is

92.7 × 62 = 5,747.4 m²

the area of the circle is

pi × r² = pi × 31² = pi × 961 = 3,019.07054... m²

the total area is then

5,747.4 + 3,019.07054... = 8,766.47054... m²

this is rounded to 1 DP

8,766.5 m²

User Leana
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