What is the area of a triangle with a base of 18cm and a height of 7cm? 2. Find the Perimeter of a circle with a ridus of 5cm. 3. Find the area of a circle with radius of 6cm. 4. Calculate the Volume for each of the cubes, (a) edge length 2cm. b. edge length 4cm. 5. Find the area of a square 3cm.

Here are the solutions to your math questions:

1. Area of a triangle

Step 1: Recall the formula for the area of a triangle.
The area of a triangle is given by:

$$A = \frac{1}{2} \times \text{base} \times \text{height}$$

Step 2: Substitute the given values into the formula.
Given base $= 18 \text{ cm}$ and height $= 7 \text{ cm}$.

$$A = \frac{1}{2} \times 18 \text{ cm} \times 7 \text{ cm}$$

Step 3: Calculate the area.

$$A = 9 \text{ cm} \times 7 \text{ cm}$$ $$A = 63 \text{ cm}^2$$

The area of the triangle is $\boxed{\text{63 cm}^2}$.

2. Perimeter of a circle

Step 1: Recall the formula for the perimeter (circumference) of a circle.
The circumference of a circle is given by:

$$C = 2\pi r$$

where $r$ is the radius.

Step 2: Substitute the given radius into the formula.
Given radius $r = 5 \text{ cm}$.

$$C = 2 \times \pi \times 5 \text{ cm}$$

Step 3: Calculate the circumference.

$$C = 10\pi \text{ cm}$$

Using $\pi \approx 3.14159$:

$$C \approx 10 \times 3.14159 \text{ cm}$$ $$C \approx 31.4159 \text{ cm}$$

The perimeter of the circle is $\boxed{\text{10\pi cm} \approx \text{31.42 cm}}$.

3. Area of a circle

Step 1: Recall the formula for the area of a circle.
The area of a circle is given by:

$$A = \pi r^2$$

where $r$ is the radius.

Step 2: Substitute the given radius into the formula.
Given radius $r = 6 \text{ cm}$.

$$A = \pi \times (6 \text{ cm})^2$$

Step 3: Calculate the area.

$$A = \pi \times 36 \text{ cm}^2$$ $$A = 36\pi \text{ cm}^2$$

Using $\pi \approx 3.14159$:

$$A \approx 36 \times 3.14159 \text{ cm}^2$$ $$A \approx 113.097 \text{ cm}^2$$

The area of the circle is $\boxed{\text{36\pi cm}^2 \approx \text{113.10 cm}^2}$.

4. Volume for each of the cubes

Step 1: Recall the formula for the volume of a cube.
The volume of a cube is given by:

$$V = \text{edge length}^3$$