PSLE The perimeter of figure ABCDE is (8
y + 19) cm. The perimeter of square ABCD is 12 cm.
- Find the perimeter of triangle ADE in terms of y.
- The perimeter of figure ABCDE is 51 cm. What is the value of y? Give your answer in cm.
(a)
Length of the square
= 12 ÷ 4
= 3 cm
Total lengths of AB, BC and CD
= 3 x 3
= 9 cm
Perimeter of triangle ADE
= 8
y + 19 - 3 - 3
= (8
y + 13) cm
(b)
8
y + 19 = 51
8
y = 51 - 19
8
y = 32
y = 32 ÷ 8 = 4
Value of
y = 4 cm
Answer(s): (a) (8
y + 13) cm; (b) 4 cm