PSLE The perimeter of figure PQRST is (9
s + 16) cm. The perimeter of square PQRS is 20 cm.
- Find the perimeter of triangle PST in terms of s.
- The perimeter of figure PQRST is 97 cm. What is the value of s? Give your answer in cm.
(a)
Length of the square
= 20 ÷ 4
= 5 cm
Total lengths of PQ, QR and RS
= 3 x 5
= 15 cm
Perimeter of triangle PST
= 9
s + 16 - 5 - 5
= (9
s + 6) cm
(b)
9
s + 16 = 97
9
s = 97 - 16
9
s = 81
s = 81 ÷ 9 = 9
Value of
s = 9 cm
Answer(s): (a) (9
s + 6) cm; (b) 9 cm