PSLE The perimeter of figure DEFGH is (10
x + 11) cm. The perimeter of square DEFG is 16 cm.
- Find the perimeter of triangle DGH in terms of x.
- The perimeter of figure DEFGH is 81 cm. What is the value of x? Give your answer in cm.
(a)
Length of the square
= 16 ÷ 4
= 4 cm
Total lengths of DE, EF and FG
= 3 x 4
= 12 cm
Perimeter of triangle DGH
= 10
x + 11 - 4 - 4
= (10
x + 3) cm
(b)
10
x + 11 = 81
10
x = 81 - 11
10
x = 70
x = 70 ÷ 10 = 7
Value of
x = 7 cm
Answer(s): (a) (10
x + 3) cm; (b) 7 cm