Let's solve each problem step by step using the
perimeter formula for a rectangle:
>
Perimeter of a rectangle = 2 × (Length + Width)
> Or:
> $ P = 2(L + W) $
We'll use this formula to find the missing side (L) in each case.
---
(1)
Given:
- Perimeter = 26
- One side = 9
- Find: L (the other side)
Using the formula:
$$
P = 2(L + W)
$$
$$
26 = 2(L + 9)
$$
Divide both sides by 2:
$$
13 = L + 9
$$
Subtract 9:
$$
L = 4
$$
✔ Answer: (a) 4
---
(2)
Given:
- Perimeter = 28
- One side = 9
- Find: L
$$
28 = 2(L + 9)
$$
Divide by 2:
$$
14 = L + 9
$$
Subtract 9:
$$
L = 5
$$
✔ Answer: (c) 5
---
(3)
Given:
- Perimeter = 20
- One side = 8
- Find: L
$$
20 = 2(L + 8)
$$
Divide by 2:
$$
10 = L + 8
$$
Subtract 8:
$$
L = 2
$$
✔ Answer: (d) 2
---
(4)
Given:
- Perimeter = 28
- One side = 7
- Find: L
$$
28 = 2(L + 7)
$$
Divide by 2:
$$
14 = L + 7
$$
Subtract 7:
$$
L = 7
$$
✔ Answer: (b) 7
---
✔ Final Answers:
1.
(a) 4
2.
(c) 5
3.
(d) 2
4.
(b) 7
These are all correct based on the perimeter formula.
Parent Tip: Review the logic above to help your child master the concept of 5th grade area and perimeter worksheet.
