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Question
Length of tape required to cover the edges of a semicircular disc of radius 10 cm is ______.
Options
62.8 cm
51.4 cm
31.4 cm
15.7 cm
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Solution
Length of tape required to cover the edges of a semicircular disc of radius 10 cm is 51.4 cm.
Explanation:
In order to find the length of tape required to cover the edges of a semi-circular disc, we have to find the perimeter of semi-circle
From the above figure it is clear that,
Perimeter of semi-circle = Circumference of semi-circle + Diameter
∵ Circumference of semi-Circle = `(2πr)/2`
= π × r
= `22/7 xx 10`
= `220/7`
= 31.4 cm
∴ Total tape required = 31.4 + 2 × 10 ...[∵ Diameter = 2 × radius]
= 51.4 cm
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