PSLE The perimeter of figure PQRST is (5
d + 10) cm. The perimeter of square PQRS is 8 cm.
- Find the perimeter of triangle PST in terms of d.
- The perimeter of figure PQRST is 30 cm. What is the value of d? Give your answer in cm.
(a)
Length of the square
= 8 ÷ 4
= 2 cm
Total lengths of PQ, QR and RS
= 3 x 2
= 6 cm
Perimeter of triangle PST
= 5
d + 10 - 2 - 2
= (5
d + 6) cm
(b)
5
d + 10 = 30
5
d = 30 - 10
5
d = 20
d = 20 ÷ 5 = 4
Value of
d = 4 cm
Answer(s): (a) (5
d + 6) cm; (b) 4 cm