PSLECharlie had 2.3 m of wire. He used some of it to make the figure as shown.
- How much of the wire did Andy use to make the figure? Leave your answer in the simplest form in terms of r.
- If r = 13, how much of the wire was not used to make the figure? Leave your answer in meters.
(a)
Total length of wire used
= r + r + r + (2r - 7) + (r + 15)
= r + r + r + 2r + r - 7 + 15
= (6 r + 8) cm
(b)
1 m = 100 cm
2.3 m = 230 cm
Total length of wire used if r = 13
= 6 r + 8
= 6(13) + 8
= 78 + 8
= 86 cm
Total length of wire not used
= 230 - 86
= 144 cm
1 cm = 0.01 m
144 cm = 1.44 m
Answer(s): (a) (6r + 8) cm; (b) 1.44 m