PSLE The perimeter of figure BCDEF is (9
j + 24) cm. The perimeter of square BCDE is 16 cm.
- Find the perimeter of triangle BEF in terms of j.
- The perimeter of figure BCDEF is 105 cm. What is the value of j? Give your answer in cm.
(a)
Length of the square
= 16 ÷ 4
= 4 cm
Total lengths of BC, CD and DE
= 3 x 4
= 12 cm
Perimeter of triangle BEF
= 9
j + 24 - 4 - 4
= (9
j + 16) cm
(b)
9
j + 24 = 105
9
j = 105 - 24
9
j = 81
j = 81 ÷ 9 = 9
Value of
j = 9 cm
Answer(s): (a) (9
j + 16) cm; (b) 9 cm