PSLEGeorge had 3.3 m of string. He used some of it to make the figure as shown.
- How much of the string did Andy use to make the figure? Leave your answer in the simplest form in terms of r.
- If r = 30, how much of the string was not used to make the figure? Leave your answer in meters.
(a)
Total length of string used
= r + r + r + (3r - 3) + (r + 20)
= r + r + r + 3r + r - 3 + 20
= (7 r + 17) cm
(b)
1 m = 100 cm
3.3 m = 330 cm
Total length of string used if r = 30
= 7 r + 17
= 7(30) + 17
= 210 + 17
= 227 cm
Total length of string not used
= 330 - 227
= 103 cm
1 cm = 0.01 m
103 cm = 1.03 m
Answer(s): (a) (7r + 17) cm; (b) 1.03 m