PSLEEric had 3.7 m of rope. He used some of it to make the figure as shown.
- How much of the rope did Andy use to make the figure? Leave your answer in the simplest form in terms of r.
- If r = 20, how much of the rope was not used to make the figure? Leave your answer in meters.
(a)
Total length of rope used
= r + r + r + (3r - 6) + (r + 19)
= r + r + r + 3r + r - 6 + 19
= (7 r + 13) cm
(b)
1 m = 100 cm
3.7 m = 370 cm
Total length of rope used if r = 20
= 7 r + 13
= 7(20) + 13
= 140 + 13
= 153 cm
Total length of rope not used
= 370 - 153
= 217 cm
1 cm = 0.01 m
217 cm = 2.17 m
Answer(s): (a) (7r + 13) cm; (b) 2.17 m