PSLE The perimeter of figure FGHJK is (7
i + 23) cm. The perimeter of square FGHJ is 28 cm.
- Find the perimeter of triangle FJK in terms of i.
- The perimeter of figure FGHJK is 79 cm. What is the value of i? Give your answer in cm.
(a)
Length of the square
= 28 ÷ 4
= 7 cm
Total lengths of FG, GH and HJ
= 3 x 7
= 21 cm
Perimeter of triangle FJK
= 7
i + 23 - 7 - 7
= (7
i + 9) cm
(b)
7
i + 23 = 79
7
i = 79 - 23
7
i = 56
i = 56 ÷ 7 = 8
Value of
i = 8 cm
Answer(s): (a) (7
i + 9) cm; (b) 8 cm