PSLE The perimeter of figure BCDEF is (5
p + 15) cm. The perimeter of square BCDE is 8 cm.
- Find the perimeter of triangle BEF in terms of p.
- The perimeter of figure BCDEF is 35 cm. What is the value of p? Give your answer in cm.
(a)
Length of the square
= 8 ÷ 4
= 2 cm
Total lengths of BC, CD and DE
= 3 x 2
= 6 cm
Perimeter of triangle BEF
= 5
p + 15 - 2 - 2
= (5
p + 11) cm
(b)
5
p + 15 = 35
5
p = 35 - 15
5
p = 20
p = 20 ÷ 5 = 4
Value of
p = 4 cm
Answer(s): (a) (5
p + 11) cm; (b) 4 cm