Formula for the Area of a Triangle

To investigate why the Area of a triangle is (base x height.)

• The parallelogram is decomposed into two triangles. Move the slider from the right position to the left.​
• Compare the area of the original figure to that of the final figure.

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Explore the Area of Triangles.

• Move points A, B, and C. ​
• Observe the length of the base and height. ​
• Observe the area of the triangle.

1. What do you observe when you keep the base horizontal and slide point A left or right? ​
2. Does the area agree with your visual count of the squares inside the triangle?

Andre drew a line connecting two opposite corners of a parallelogram. Select all true statements about the triangles created by the line Andre drew.

Here below is a right triangle.