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5.An ant is moving around a few food pieces of different shapes scattered on the floor. For which food-piece would the ant have to take a longer round? Remember, the circumference of a circle can be obtained by using the expression C = \(2\pi r\), where r is the radius of the circle.


Answer :

(a)Distance covered by the ant to take a round:
\(=\frac{1}2\times2\pi r+2r\)

\(=\pi r+2r\)

\(=\frac{22}7\times1.4+2\times1.4\)

\(=22\times 0.2+2.8\)

\(=4.4+2.8=7.2cm\)

(b)Distance covered by the ant to take a round:
\(=\frac{1}2 \times 2\pi r+1.5+1.5+2.8\)

\(=\pi r+5.8\)

\(=\frac{22}7\times 0.2+5.8\)

\(=4.4+5.8\)

\(=10.2cm\)

(c)Distance covered by the ant to take a round:
\(=\frac{1}2 \times 2\pi r+2+2\)

\(=\pi r+4\)

\(=\frac{22}7\times 1.4+4\)

\(=4.4+4\)

\(=8.4cm\)

So, among all the given paths, in path (b) ant has to travel a larger distance for food piece than others.

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