PSLE Figure 1 shows a trapezium which has a perimeter of 62 cm. Tina joins three such trapeziums to form Figure 2 which has a perimeter of 130 cm.
- Find the length of AB.
- Tina joins another four such trapeziums to form Figure 3 which has an area of 868 cm2. Find the length of XY.
(a)
Perimeter of three separate trapeziums
= 3 x 62
= 186 cm
Number of overlapping ABs = 4
Length of 4 ABs
= 186 - 130
= 56 cm
Length of 1 AB
= 56 ÷ 4
= 14 cm
(b)
Area of 2 rectangles
= 868 ÷ 2
= 434 cm
2 Length of the rectangle
= 434 ÷ 14
= 31 cm
Length of XY
= 31 - 14 - 8
= 9 cm
Answer(s): (a) 14 cm; (b) 9 cm