PSLE The perimeter of figure EFGHJ is (10
b + 25) cm. The perimeter of square EFGH is 20 cm.
- Find the perimeter of triangle EHJ in terms of b.
- The perimeter of figure EFGHJ is 95 cm. What is the value of b? Give your answer in cm.
(a)
Length of the square
= 20 ÷ 4
= 5 cm
Total lengths of EF, FG and GH
= 3 x 5
= 15 cm
Perimeter of triangle EHJ
= 10
b + 25 - 5 - 5
= (10
b + 15) cm
(b)
10
b + 25 = 95
10
b = 95 - 25
10
b = 70
b = 70 ÷ 10 = 7
Value of
b = 7 cm
Answer(s): (a) (10
b + 15) cm; (b) 7 cm