PSLE The perimeter of figure DEFGH is (9
h + 24) cm. The perimeter of square DEFG is 20 cm.
- Find the perimeter of triangle DGH in terms of h.
- The perimeter of figure DEFGH is 105 cm. What is the value of h? Give your answer in cm.
(a)
Length of the square
= 20 ÷ 4
= 5 cm
Total lengths of DE, EF and FG
= 3 x 5
= 15 cm
Perimeter of triangle DGH
= 9
h + 24 - 5 - 5
= (9
h + 14) cm
(b)
9
h + 24 = 105
9
h = 105 - 24
9
h = 81
h = 81 ÷ 9 = 9
Value of
h = 9 cm
Answer(s): (a) (9
h + 14) cm; (b) 9 cm