To understand the connection between triangles and rectangles.
Materials
Construction paper
Ruler
Pen or pencil
Develop the formula for area of a triangle
Area of rectangles
To complete this activity, we'll need to recall how we find the area of a rectangle.
The area of a rectangle can be found by multiplying two side lengths together.
Often the sides of rectangles are called length and width, so we can find the area by multiplying these two values together, l \times w.
Complete the following procedure:
Measure and label the side lengths of your piece of paper. Be sure to include the units.
Find the area and jot it down on the piece of paper.
Using your ruler, draw a line from one corner to another corner that splits the rectangle in half.
Investigate
Consider the following questions once you have completed the procedure above.
1.
What shapes are created once you split your original shape in half?
2.
What is the area of half of your original shape?
3.
What can you say about the connection between area of rectangles and area of triangles?
Answer the questions below after you have completed the activity.
Discussion
1.
Knowing how the area of a triangle relates to the area of a rectangle, can you create a formula to represent the area of a triangle? Use the variables b for the base of the triangle and h for the height of the triangle.
Outcomes
6.G.A.1
Find area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
