Circle P6 2009 SA2 P2 Rulang Q3

3. A piece of wire is bent to form two semicircles as shown below. Find the length of the wire used. (Take π = 3.14)

3.14 x 5 = 15.7

3.14 x 10 = 31.4

5 + 5 + 15.7 + 31.4 = 57.1 cm

Circle P6 2009 SA2 P2 Rulang Q12

12. The figure below is made up of a semicircle, 2 isosceles triangles and a square. If the area of each isosceles triangle is 32 cm², find the area of the semicircle. (Take π = 3.14)

32 x 2 = 64

64 = 8 x 8

8 x 3 = 24

24 ÷ 2 = 12

1/2 x 3.14 x 12 x 12 = 226.08 cm²

The area of the semicircle is 226.08 cm².