Area and Properties of Trapezoids

This lesson teaches how to find the area of a trapezoid by composing it into a parallelogram. It begins with a review of calculating the area of rectangles and parallelograms. The lesson then demonstrates how to create a congruent trapezoid, flip it, and form a rectangle to find the area. An example with an isosceles trapezoid is provided, showing how to form a parallelogram and calculate its area. The lesson concludes by highlighting common mistakes, such as forgetting to halve the area of the composed shape to find the trapezoid's area.

What is the main method taught in this lesson to find the area of a trapezoid?

• By composing a parallelogram

• By using the Pythagorean theorem

• By using the formula for a circle

• By dividing it into triangles

How do you calculate the area of a rectangle?

• Length times width

• Base times height

• Side squared

• Diameter times radius

What shape is formed when a congruent trapezoid is flipped and combined with the original?

• Hexagon

• Rectangle

• Circle

• Triangle

If the area of the rectangle formed by two trapezoids is 105 square units, what is the area of one trapezoid?

• 52.5 square units

• 105 square units

• 210 square units

• 26.25 square units

What is the relationship between the top and bottom of a trapezoid?

• They are perpendicular

• They are parallel

• They are equal in length

• They form a right angle

In the example of an isosceles trapezoid, what shape is created by flipping a congruent trapezoid?

• Circle

• Rectangle

• Parallelogram

• Square

What is the area of the original isosceles trapezoid if the parallelogram's area is 48 square units?

• 12 square units

• 48 square units

• 24 square units

• 36 square units

What is the base of the parallelogram in the isosceles trapezoid example?

• 5 units

• 21 units

• 16 units

• 3 units

What is the height of the parallelogram in the isosceles trapezoid example?

• 21 units

• 3 units

• 16 units

• 5 units

What is a common mistake when finding the area of a trapezoid by composing a larger shape?

• Using the wrong units

• Forgetting to multiply by the height

• Calculating the perimeter instead of the area

• Forgetting to divide the area of the larger shape by two