Let's solve each triangle area problem step by step using the formula for the area of a triangle:
🔷 Formula:
$$
\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}
$$
We’ll go through each triangle one by one.
---
✔ Triangle 1
- Base = 5 cm
- Height = 3 cm
$$
\text{Area} = \frac{1}{2} \times 5 \times 3 = \frac{15}{2} = 7.5 \text{ cm}^2
$$
✔ Answer: $ \boxed{7.5} $ square cm
---
✔ Triangle 2
- Base = 4 cm
- Height = 7 cm
$$
\text{Area} = \frac{1}{2} \times 4 \times 7 = \frac{28}{2} = 14 \text{ cm}^2
$$
✔ Answer: $ \boxed{14} $ square cm
---
✔ Triangle 3
- Base = 8 cm
- Height = 6 cm
$$
\text{Area} = \frac{1}{2} \times 8 \times 6 = \frac{48}{2} = 24 \text{ cm}^2
$$
✔ Answer: $ \boxed{24} $ square cm
---
✔ Triangle 4
- Base = 10 cm
- Height = 15 cm
$$
\text{Area} = \frac{1}{2} \times 10 \times 15 = \frac{150}{2} = 75 \text{ cm}^2
$$
✔ Answer: $ \boxed{75} $ square cm
---
✔ Triangle 5
- Base = 20 cm
- Height = 9 cm
$$
\text{Area} = \frac{1}{2} \times 20 \times 9 = \frac{180}{2} = 90 \text{ cm}^2
$$
✔ Answer: $ \boxed{90} $ square cm
---
✔ Final Answers:
| Triangle | Area (cm²) |
|--------|------------|
| 1 | 7.5 |
| 2 | 14 |
| 3 | 24 |
| 4 | 75 |
| 5 | 90 |
---
📌 Summary:
Use the formula:
$$
\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}
$$
Make sure to identify the
base and the
perpendicular height (not just any side). In these right triangles, the two legs are often base and height.
✔ All areas have been calculated correctly!
Let me know if you'd like this as a printable answer sheet!
Parent Tip: Review the logic above to help your child master the concept of fifth grade geometry worksheet.