PSLE Figure 1 shows a trapezium which has a perimeter of 66 cm. Tammy joins three such trapeziums to form Figure 2 which has a perimeter of 142 cm.
- Find the length of AB.
- Tammy joins another four such trapeziums to form Figure 3 which has an area of 980 cm2. Find the length of XY.
(a)
Perimeter of three separate trapeziums
= 3 x 66
= 198 cm
Number of overlapping ABs = 4
Length of 4 ABs
= 198 - 142
= 56 cm
Length of 1 AB
= 56 ÷ 4
= 14 cm
(b)
Area of 2 rectangles
= 980 ÷ 2
= 490 cm
2 Length of the rectangle
= 490 ÷ 14
= 35 cm
Length of XY
= 35 - 14 - 10
= 11 cm
Answer(s): (a) 14 cm; (b) 11 cm