GB-26-03-001 · Semicircle perimeter
A semicircular window has radius 45 cm. Work out its total perimeter, including the straight edge. Give your answer to 1 decimal place.
Perimeter of a Semicircle
Booklet p. 38 & p. 83
Method
1) Curved arc length = ½ × 2πr = πr
2) Add straight diameter (2r) to get total perimeter
Worked Example (GB-26-03-001)
1)
Curved edge = 45π.
2)
Add the diameter, 90.
3)
231.4 cm
Ans =
231.4 cm