1. The problem is to find the formula for the area of a parallelogram. 2. The area $A$ of a parallelogram can be calculated using the formula: $$A = b \times h$$ where $b$ is the length of the base and $h$ is the height (the perpendicular distance from the base to the opposite side). 3. Important rule: The height must be perpendicular to the base, not the length of the slant side. 4. To understand this, imagine a parallelogram with base $b$ and height $h$. The area is the same as the area of a rectangle with the same base and height. 5. So, if you know the base and the height, multiply them to get the area. Final answer: $$A = b \times h$$