PSLE The perimeter of figure ABCDE is (10
s + 20) cm. The perimeter of square ABCD is 16 cm.
- Find the perimeter of triangle ADE in terms of s.
- The perimeter of figure ABCDE is 100 cm. What is the value of s? Give your answer in cm.
(a)
Length of the square
= 16 ÷ 4
= 4 cm
Total lengths of AB, BC and CD
= 3 x 4
= 12 cm
Perimeter of triangle ADE
= 10
s + 20 - 4 - 4
= (10
s + 12) cm
(b)
10
s + 20 = 100
10
s = 100 - 20
10
s = 80
s = 80 ÷ 10 = 8
Value of
s = 8 cm
Answer(s): (a) (10
s + 12) cm; (b) 8 cm