PSLE The perimeter of figure DEFGH is (10
d + 18) cm. The perimeter of square DEFG is 12 cm.
- Find the perimeter of triangle DGH in terms of d.
- The perimeter of figure DEFGH is 68 cm. What is the value of d? Give your answer in cm.
(a)
Length of the square
= 12 ÷ 4
= 3 cm
Total lengths of DE, EF and FG
= 3 x 3
= 9 cm
Perimeter of triangle DGH
= 10
d + 18 - 3 - 3
= (10
d + 12) cm
(b)
10
d + 18 = 68
10
d = 68 - 18
10
d = 50
d = 50 ÷ 10 = 5
Value of
d = 5 cm
Answer(s): (a) (10
d + 12) cm; (b) 5 cm