PSLEKen had 3.9 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 b.
- If b = 20, how much of the wire was not used to make the figure? Leave your answer in meters.
(a)
Total length of wire used
= b + b + b + (2b - 10) + (b + 12)
= b + b + b + 2b + b - 10 + 12
= (6 b + 2) cm
(b)
1 m = 100 cm
3.9 m = 390 cm
Total length of wire used if b = 20
= 6 b + 2
= 6(20) + 2
= 120 + 2
= 122 cm
Total length of wire not used
= 390 - 122
= 268 cm
1 cm = 0.01 m
268 cm = 2.68 m
Answer(s): (a) (6b + 2) cm; (b) 2.68 m