Use the image to answer the question.
An illustration shows a 5 by 9 grid labeled Triangle C. Triangle C is graphed on the grid.
Use decomposition and rearranging to model the area formula of triangle C
. What is the area of triangle C
in square units?
To model the area formula of Triangle C, we can decompose it into two right triangles and a rectangle.
One right triangle has a base of 4 units and height of 5 units.
The other right triangle has a base of 5 units and height of 4 units.
The rectangle has a base of 5 units and height of 4 units.
Therefore, the total area of Triangle C is the sum of the areas of the two right triangles and the rectangle:
Area = (1/2 * 4 * 5) + (1/2 * 5 * 4) + (5 * 4)
Area = (1/2 * 20) + (1/2 * 20) + 20
Area = 10 + 10 + 20
Area = 40 square units
Therefore, the area of Triangle C is 40 square units.