PSLEIvan had 3.3 m of thread. He used some of it to make the figure as shown.
- How much of the thread did Andy use to make the figure? Leave your answer in the simplest form in terms of y.
- If y = 21, how much of the thread was not used to make the figure? Leave your answer in meters.
(a)
Total length of thread used
= y + y + y + (3y - 6) + (y + 18)
= y + y + y + 3y + y - 6 + 18
= (7 y + 12) cm
(b)
1 m = 100 cm
3.3 m = 330 cm
Total length of thread used if y = 21
= 7 y + 12
= 7(21) + 12
= 147 + 12
= 159 cm
Total length of thread not used
= 330 - 159
= 171 cm
1 cm = 0.01 m
171 cm = 1.71 m
Answer(s): (a) (7y + 12) cm; (b) 1.71 m