Let's solve each part:

1. Square with side 4 cm: $\text{Area} = \text{side}^2 = 4 \times 4 = 16 \, \text{cm}^2$

2. Triangle with base and height of 4 cm: $\text{Area} = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 4 \times 4 = 8 \, \text{cm}^2$

3. Circle with radius 4 cm (using $\pi = 3.14$): $\text{Area} = \pi \times \text{radius}^2 = 3.14 \times 4^2 = 3.14 \times 16 = 50.24 \, \text{cm}^2$

The answers are:

• a. 16 cm²
• b. 8 cm²
• c. 50.24 cm²

Would you like more details on any of these solutions?

Here are some related questions to expand understanding:

1. How would the area change if the side of the square was doubled?
2. What is the formula for the area of a triangle when only the lengths of the sides are known?
3. How does the value of $\pi$ impact the area of a circle calculation?
4. How can you find the area of a triangle if only one angle is given along with two sides?
5. What are some real-world applications of calculating areas of these shapes?

Tip: When calculating areas, always remember to square the relevant measurements and check units.