The side of a rhombus is 10cm long, correct to the nearest whole number. Between what limits should the perimeter P lie?
A
39cm ≤ P ≤41cm
B
38cm ≤ P < 42cm
C
38.5 ≤ P ≤ 41.5cm
D
38.5 ≤ P ≤ 40cm
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
If the side = 10 cm, correct to the nearest whole number, then
The side ranges from 9.5 cm to 10.5 cm. (9.5 \(\leq\) s < 10.5)
Perimeter of a rhombus = 4 x side
\(\therefore\) 4 x 9.5 \(\leq\) perimeter < 4 x 10.5
= 38 cm \(\leq\) P < 42 cm
Source: Myschool Past Questions Archive (Record #26380)