Area of Rectangles and Parallelograms Guided Practice Lesson

Review Vocabulary: Rectangle

Rectangle: A 4-sided flat shape with straight sides where all interior angles are right angles (90°) and opposite sides are parallel and of equal length.

Rectangles - Review

To find the area of a parallelogram it is important to understand their similarities to rectangles.

In a rectangle there is a length and a width.

Rectangle Area:

Review

To find the area of a rectangle, you multiply its length x width. The formula is :

Area = Length x Width

Multiple Choice

What is the area of this rectangle?

• 20 square feet

• 40 square feet

• 100 square feet

• 96 square feet

Multiple Choice

What is the area of this rectangle?

• 96 square cm

• 84 square cm

• 38 square cm

• 75 square cm

New Vocabulary: Parallelogram

Parallelogram: A flat shape with 4 straight sides where opposite sides are parallel, opposite sides are equal and opposite angles are equal.

Parallelograms

Parallelograms have a base and a height. The height must have a 90 degree angle so the slanted sides are different from the height of the shape.

Parallelograms

Parallelograms height can sometimes be shown outside the shape like in this example the height is 4, the base is 5.

Parallelogram Area

To find the are of a parallelogram - you multiply the base times the height. The formula is:

Area = base x height

Parallelogram Area

To find the area of this parallelogram we multiply base x height.

Area = 7 x 4 = 28 square units

**Notice we did not use the slanted side (5) to find the area.

Parallelogram Area

Area = base x height

Area = 6 x 10

Area = 60 square centimeters

**Notice: we used 10 as the base and 6 as the height, the slanted side (7) was not used to find the area

Multiple Choice

What is the base of this parallelogram ?

• 5 cm

• 35 cm

• 7 cm

• 15 cm

Multiple Choice

If we were finding the area of this parallelogram, which value would we NOT use?

• 2 m

• 2.5 m

• 1.8 m

Multiple Choice

If you were finding the area of this parallelogram, what two values would you multiply, or in other words, what. is the base and height?

• 7 and 15

• 5 and 15

• 7 and 5

Multiple Choice

What is the height of this parallelogram?

• 7 cm

• 5 cm

• 15cm

• 12 cm

Multiple Choice

What is the area of this parallelogram?

• 75 square cm

• 35 square cm

• 15 square cm

• 105 square cm

Multiple Choice

What is the area of this parallelogram?

• 20 suare cm

• 25 square cm

• 15 square cm

• 50 square cm

Multiple Choice

Find the area. 

• 27 feet²
• 213.5 feet
• 182 feet²
• 2775.5 feet

Multiple Choice

Determine the area of the parallelogram.

• 19.8 square inches

• 47.2 square inches

• 23.6 square inches

• 9.9 square inches

Multiple Choice

Find the area of the figure.

• 10 cm²
• 24 cm²
• 12 cm²
• 20 cm²