PSLE The perimeter of figure EFGHJ is (10
k + 15) cm. The perimeter of square EFGH is 16 cm.
- Find the perimeter of triangle EHJ in terms of k.
- The perimeter of figure EFGHJ is 105 cm. What is the value of k? Give your answer in cm.
(a)
Length of the square
= 16 ÷ 4
= 4 cm
Total lengths of EF, FG and GH
= 3 x 4
= 12 cm
Perimeter of triangle EHJ
= 10
k + 15 - 4 - 4
= (10
k + 7) cm
(b)
10
k + 15 = 105
10
k = 105 - 15
10
k = 90
k = 90 ÷ 10 = 9
Value of
k = 9 cm
Answer(s): (a) (10
k + 7) cm; (b) 9 cm