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Area of a Trapezoid - Lesson 11-3

Today we talked about the area of a trapezoid. To find this, we started with a trapezoid (the red one), made a copy of it (the yellow one), and rotated it 180 degrees:

Derivation of the Area of a Trapezoid - Step 1

Next, we translated it up to form a parallelogram (the combination of both trapezoids). Using the parallelogram area formula, we were able to find a formula for the area of the trapezoid:

Derivation of the Area of a Trapezoid - Step 2

We then defined a median of a trapezoid and learned about two of its properties:

Definition & Properties of the Median of a Trapezoid

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Class Notes
Lesson 11-1
Lesson 11-2
Lesson 11-3
Lesson 11-4
Quiz Topics
Lesson 11-5
Lesson 11-6
Lesson 11-7
Lesson 11-8
Test Topics
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