PSLE The perimeter of figure CDEFG is (8
j + 14) cm. The perimeter of square CDEF is 12 cm.
- Find the perimeter of triangle CFG in terms of j.
- The perimeter of figure CDEFG is 86 cm. What is the value of j? Give your answer in cm.
(a)
Length of the square
= 12 ÷ 4
= 3 cm
Total lengths of CD, DE and EF
= 3 x 3
= 9 cm
Perimeter of triangle CFG
= 8
j + 14 - 3 - 3
= (8
j + 8) cm
(b)
8
j + 14 = 86
8
j = 86 - 14
8
j = 72
j = 72 ÷ 8 = 9
Value of
j = 9 cm
Answer(s): (a) (8
j + 8) cm; (b) 9 cm