PSLEJustin had 3.8 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 a.
- If a = 14, how much of the wire was not used to make the figure? Leave your answer in meters.
(a)
Total length of wire used
= a + a + a + (3a - 9) + (a + 14)
= a + a + a + 3a + a - 9 + 14
= (7 a + 5) cm
(b)
1 m = 100 cm
3.8 m = 380 cm
Total length of wire used if a = 14
= 7 a + 5
= 7(14) + 5
= 98 + 5
= 103 cm
Total length of wire not used
= 380 - 103
= 277 cm
1 cm = 0.01 m
277 cm = 2.77 m
Answer(s): (a) (7a + 5) cm; (b) 2.77 m