PSLE The perimeter of figure QRSTU is (10
r + 16) cm. The perimeter of square QRST is 12 cm.
- Find the perimeter of triangle QTU in terms of r.
- The perimeter of figure QRSTU is 56 cm. What is the value of r? Give your answer in cm.
(a)
Length of the square
= 12 ÷ 4
= 3 cm
Total lengths of QR, RS and ST
= 3 x 3
= 9 cm
Perimeter of triangle QTU
= 10
r + 16 - 3 - 3
= (10
r + 10) cm
(b)
10
r + 16 = 56
10
r = 56 - 16
10
r = 40
r = 40 ÷ 10 = 4
Value of
r = 4 cm
Answer(s): (a) (10
r + 10) cm; (b) 4 cm