PSLE The perimeter of figure KLMNP is (5
r + 19) cm. The perimeter of square KLMN is 24 cm.
- Find the perimeter of triangle KNP in terms of r.
- The perimeter of figure KLMNP is 54 cm. What is the value of r? Give your answer in cm.
(a)
Length of the square
= 24 ÷ 4
= 6 cm
Total lengths of KL, LM and MN
= 3 x 6
= 18 cm
Perimeter of triangle KNP
= 5
r + 19 - 6 - 6
= (5
r + 7) cm
(b)
5
r + 19 = 54
5
r = 54 - 19
5
r = 35
r = 35 ÷ 5 = 7
Value of
r = 7 cm
Answer(s): (a) (5
r + 7) cm; (b) 7 cm