Visualizing The Area of a Triangle Formula | Emerging Area of a Triangle From Area of a Rectangle

All Math Is Visual number talk Prompts are useful for introducing and/or reinforcing mathematics concepts and skills to build fluency and flexibility with numbers and conceptualizing mathematics. While we suggest using these prompts at the beginning of a math lesson, they could be useful at any point during a math block as well as at home to strengthen (and excite) your child mathematically.

This math talk serves to develop a deeper understanding of the following big ideas:

The area of a rectangle can be determined by multiplying the length of its base by the length of its height;
The area of a rectangle is used to determine the area formulas for other polygons;
Using “base” and “height” rather than “length” and “width” can support student understanding when determining the area formulas for triangles and all quadrilaterals;
A parallelogram is any quadrilateral with two sets of parallel sides;
A rectangle is a parallelogram;
The relationships between rectangles, parallelograms, and triangles can be used to determine area formulas;
Any triangle can be doubled to create a parallelogram;
Congruent shapes have the same size and shape, but not necessarily the same orientation.

Notice the "PAUSE" prompts throughout which provide appropriate points to stop the video and give students time to think through their approaches using mathematical models as a means to see their strategies through.


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