PSLE The perimeter of figure CDEFG is (7
i + 14) cm. The perimeter of square CDEF is 8 cm.
- Find the perimeter of triangle CFG in terms of i.
- The perimeter of figure CDEFG is 77 cm. What is the value of i? Give your answer in cm.
(a)
Length of the square
= 8 ÷ 4
= 2 cm
Total lengths of CD, DE and EF
= 3 x 2
= 6 cm
Perimeter of triangle CFG
= 7
i + 14 - 2 - 2
= (7
i + 10) cm
(b)
7
i + 14 = 77
7
i = 77 - 14
7
i = 63
i = 63 ÷ 7 = 9
Value of
i = 9 cm
Answer(s): (a) (7
i + 10) cm; (b) 9 cm