Let's solve each triangle's area using the formula:
$$
\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}
$$
We’ll go through each triangle one by one.
---
1.
- Base = 18 cm
- Height = 12 cm
$$
\text{Area} = \frac{1}{2} \times 18 \times 12 = 9 \times 12 = 108 \, \text{cm}^2
$$
✔ Answer: 108 cm²
---
2.
- Base = 33 in
- Height = 22 in
$$
\text{Area} = \frac{1}{2} \times 33 \times 22 = 16.5 \times 22 = 363 \, \text{in}^2
$$
✔ Answer: 363 in²
---
3.
- Base = 6 m
- Height = 9 m
$$
\text{Area} = \frac{1}{2} \times 6 \times 9 = 3 \times 9 = 27 \, \text{m}^2
$$
✔ Answer: 27 m²
---
4.
- Base = 11 cm
- Height = 13 cm
(Note: The height is drawn from the top vertex to the base, so it's perpendicular.)
$$
\text{Area} = \frac{1}{2} \times 11 \times 13 = 5.5 \times 13 = 71.5 \, \text{cm}^2
$$
✔ Answer: 71.5 cm²
---
5.
- This is a right triangle with legs 5 yd and 7 yd.
In a right triangle, the two legs can be used as base and height.
$$
\text{Area} = \frac{1}{2} \times 5 \times 7 = 2.5 \times 7 = 17.5 \, \text{yd}^2
$$
✔ Answer: 17.5 yd²
---
6.
- Right triangle with legs 4 mm and 9 mm
$$
\text{Area} = \frac{1}{2} \times 4 \times 9 = 2 \times 9 = 18 \, \text{mm}^2
$$
✔ Answer: 18 mm²
---
7.
- Base = 44 mm
- Height = 28 mm
$$
\text{Area} = \frac{1}{2} \times 44 \times 28 = 22 \times 28 = 616 \, \text{mm}^2
$$
✔ Answer: 616 mm²
---
8.
- Base = 15 in
- Height = 8 in
$$
\text{Area} = \frac{1}{2} \times 15 \times 8 = 7.5 \times 8 = 60 \, \text{in}^2
$$
✔ Answer: 60 in²
---
✔ Final Answers:
| Problem | Area |
|--------|------|
| 1 | 108 cm² |
| 2 | 363 in² |
| 3 | 27 m² |
| 4 | 71.5 cm² |
| 5 | 17.5 yd² |
| 6 | 18 mm² |
| 7 | 616 mm² |
| 8 | 60 in² |
---
💡
Tip: Always make sure the height is
perpendicular to the base. In right triangles, you can use the two legs as base and height.
Let me know if you'd like this formatted for printing or need help with units!
Parent Tip: Review the logic above to help your child master the concept of finding the area of a triangle worksheet.
