PSLEBen had 3.4 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 s.
- If s = 19, how much of the thread was not used to make the figure? Leave your answer in meters.
(a)
Total length of thread used
= s + s + s + (3s - 9) + (s + 18)
= s + s + s + 3s + s - 9 + 18
= (7 s + 9) cm
(b)
1 m = 100 cm
3.4 m = 340 cm
Total length of thread used if s = 19
= 7 s + 9
= 7(19) + 9
= 133 + 9
= 142 cm
Total length of thread not used
= 340 - 142
= 198 cm
1 cm = 0.01 m
198 cm = 1.98 m
Answer(s): (a) (7s + 9) cm; (b) 1.98 m