The perimeter of a semicircle is 25.7 kilometers. What is the semicircle's diameter?

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Answer 1 · 2018-02-18T07:45:30

Diameter of the semicircle = 10 km.

perimeter of semicircle = #1/2# the circumference + diameter

Given: perimeter of semicircle =# 25.7 km#

Circumference of circle with radius #r#= # 2 pi r# where #2r #= diameter

#=> 25.7 = 1/2 xx 2 pi r + 2r#

#=> 25.7 = pi r +2r = r ( pi +2)#

#=> 25.7 = r( 3.14 +2 )= r(5.14)#

#=> r = 25.7 / 5.14 = 5#

#therefore radius = 5 km#

#=> diameter = 2r = 10 km#