A window is shaped like a semicircle of radius 14 cm. What length of metal strip is needed to go all round its edge, including the straight edge? Take $\pi = \frac{22}{7}$ .

44 cmCorrect answerYour answer58 cmCorrect answerYour answer72 cmCorrect answerYour answer88 cmCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Curved edge = half the circumference = $\pi r = \frac{22}{7} \times 14 = 44$ cm.
Straight edge = diameter = 28 cm.
Total = $44 + 28 = 72$ cm.

Worth noting

44 cm leaves out the straight edge, and 88 cm is the full circle's circumference.

Ten questions from Mensuration: Areas and Volumes, at your own pace.

Ten questions from Mensuration: Areas and Volumes, at your own pace.

A window is shaped like a semicircle of radius 14 cm. What length of metal strip is needed to go all round its edge, including the straight edge? Take π=227\pi = \frac{22}{7}π=722​.