Use the following formula to work out the area of a **rectangle**:

We must know the base length and the perpendicular height from the base to the top.

Area of **rectangle** = base × height

Now, try this with a piece of paper.

Start with a rectangle.

Cut off a right-angled triangle from the left-hand side and separate the two pieces.

The area of the two pieces together will be the same as the original rectangle.

Move the right-angled triangle over to the right-hand side.

The area still hasn't changed.

Join the two pieces to form a parallelogram.

The area of this parallelogram is the same as the original rectangle.

**Area of Parallelograms**

We must know the **base **length and the perpendicular **height **from the base to the top. *(NOT the slant height)*

Area of **parallelogram** = base × height

**Example**

Calculate the area of this parallelogram in cm^{2}.

**Answer**

To calculate the area, we must know the **base **length and the perpendicular **height **from the base to the top. *(NOT the slant height)*

The base length is 10 cm.

The slant height is 7 cm, which we do not need.

The perpendicular height is 6 cm.

**Area** = Base × Height = 10 × 6 = **60 cm ^{2}**