PSLE The perimeter of figure PQRST is (4
r + 16) cm. The perimeter of square PQRS is 16 cm.
- Find the perimeter of triangle PST in terms of r.
- The perimeter of figure PQRST is 48 cm. What is the value of r? Give your answer in cm.
(a)
Length of the square
= 16 ÷ 4
= 4 cm
Total lengths of PQ, QR and RS
= 3 x 4
= 12 cm
Perimeter of triangle PST
= 4
r + 16 - 4 - 4
= (4
r + 8) cm
(b)
4
r + 16 = 48
4
r = 48 - 16
4
r = 32
r = 32 ÷ 4 = 8
Value of
r = 8 cm
Answer(s): (a) (4
r + 8) cm; (b) 8 cm