PSLETom had 2.6 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 r.
- If r = 24, how much of the thread was not used to make the figure? Leave your answer in meters.
(a)
Total length of thread used
= r + r + r + (2r - 10) + (r + 13)
= r + r + r + 2r + r - 10 + 13
= (6 r + 3) cm
(b)
1 m = 100 cm
2.6 m = 260 cm
Total length of thread used if r = 24
= 6 r + 3
= 6(24) + 3
= 144 + 3
= 147 cm
Total length of thread not used
= 260 - 147
= 113 cm
1 cm = 0.01 m
113 cm = 1.13 m
Answer(s): (a) (6r + 3) cm; (b) 1.13 m