PSLE Figure 1 shows a trapezium which has a perimeter of 61 cm. Julie joins three such trapeziums to form Figure 2 which has a perimeter of 127 cm.
- Find the length of AB.
- Julie joins another four such trapeziums to form Figure 3 which has an area of 812 cm2. Find the length of XY.
(a)
Perimeter of three separate trapeziums
= 3 x 61
= 183 cm
Number of overlapping ABs = 4
Length of 4 ABs
= 183 - 127
= 56 cm
Length of 1 AB
= 56 ÷ 4
= 14 cm
(b)
Area of 2 rectangles
= 812 ÷ 2
= 406 cm
2 Length of the rectangle
= 406 ÷ 14
= 29 cm
Length of XY
= 29 - 14 - 6
= 9 cm
Answer(s): (a) 14 cm; (b) 9 cm