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42 votes
42 votes
Here is a semicircle of diameter d.

the perimeter of the shape is 51.42cm
calculate the value of the diameter d

Here is a semicircle of diameter d. the perimeter of the shape is 51.42cm calculate-example-1
User Burak Guzel
by
2.6k points

1 Answer

22 votes
22 votes

Answer:

a) D
(\pi d)/(2)+d

b) 20 cm

Explanation:

a) circumference of circle =
\pi d

Therefore, perimeter of shape =
(\pi d)/(2)+d

b) Given:

  • perimeter = 51.42 cm

  • \pi = 3.142


\implies 51.42 =(3.142d)/(2)+d


\implies 51.42 =(3.142d)/(2)+(2d)/(2)


\implies 51.42 =(3.142d+2d)/(2)


\implies 51.42* 2 =3.142d+2d


\implies 102.84 =5.142d


\implies d=(102.84)/(5.142)


\implies d=20

User Jdmaldonado
by
2.9k points