PSLE The perimeter of figure CDEFG is (10
j + 14) cm. The perimeter of square CDEF is 24 cm.
- Find the perimeter of triangle CFG in terms of j.
- The perimeter of figure CDEFG is 84 cm. What is the value of j? Give your answer in cm.
(a)
Length of the square
= 24 ÷ 4
= 6 cm
Total lengths of CD, DE and EF
= 3 x 6
= 18 cm
Perimeter of triangle CFG
= 10
j + 14 - 6 - 6
= (10
j + 2) cm
(b)
10
j + 14 = 84
10
j = 84 - 14
10
j = 70
j = 70 ÷ 10 = 7
Value of
j = 7 cm
Answer(s): (a) (10
j + 2) cm; (b) 7 cm