Warmup
Activity #1
Identify a Base and a Corresponding Height of a Triangle.
Unless you are counting the squares that are enclosed within a triangle, the length of the base and the height of the triangle are needed if you have to find the area by calculation. In the applet below, you are going to locate the corresponding height of a triangle for a given base.
Activity #2
Why the Area of a Triangle is (base x height.)
We already know that a parallelogram is composed of two congruent triangles. So its area is found in relation to the area of a parallelogram. In this activity, you are going to investigate how this comes about.
Activity #3
Explore the Area of Triangles.
Follow the instructions below and interact with the applet to explore the area of a 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?
Quiz Time
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