1. The problem is to understand and use the formula for the volume of a cylinder, which is given by $$V = r^2 \cdot \pi \cdot h$$ where $V$ is the volume, $r$ is the radius of the base, and $h$ is the height of the cylinder. 2. This formula comes from the fact that the base of the cylinder is a circle with area $\pi r^2$, and the volume is the area of the base times the height. 3. Important rules: - $\pi$ is a constant approximately equal to 3.14159. - The radius $r$ must be squared before multiplying by $\pi$ and $h$. 4. To calculate the volume, plug in the values of $r$ and $h$ into the formula and perform the multiplication. 5. Example: If $r=3$ and $h=5$, then $$V = 3^2 \cdot \pi \cdot 5 = 9 \cdot \pi \cdot 5 = 45\pi$$ 6. The volume is $45\pi$ cubic units, which is approximately $141.37$ cubic units when $\pi$ is approximated as 3.14159. This formula is fundamental in geometry and physics when dealing with cylindrical shapes.