PSLE Figure 1 shows a trapezium which has a perimeter of 64 cm. Jaslyn joins three such trapeziums to form Figure 2 which has a perimeter of 136 cm.
- Find the length of AB.
- Jaslyn joins another four such trapeziums to form Figure 3 which has an area of 924 cm2. Find the length of XY.
(a)
Perimeter of three separate trapeziums
= 3 x 64
= 192 cm
Number of overlapping ABs = 4
Length of 4 ABs
= 192 - 136
= 56 cm
Length of 1 AB
= 56 ÷ 4
= 14 cm
(b)
Area of 2 rectangles
= 924 ÷ 2
= 462 cm
2 Length of the rectangle
= 462 ÷ 14
= 33 cm
Length of XY
= 33 - 14 - 9
= 10 cm
Answer(s): (a) 14 cm; (b) 10 cm