Question

Draw your own right triangle, with an area of 18 square units, on the coordinate plane. Then, identify the vertices of your triangle. Explain how you know that your triangle has the correct area.

Answer 1

The vertices of the triangle are (-1, 9), (-7, 3), and (-1, 3).

The distance between (-7, 3) and (-1, 3) is 6 units.

The distance between (-1, 9) and (-1, 3) is 6 units.

6 x 6 = 36 units.

36 / 2 = 18 square units.

Explanation:

Answer 2

The vertices of the attached triangle are
A(9, 0)
B(0, 4)
O(0, 0)

The leg lengths of this triangle are 9 and 4 units. Its area can be computed using the formula for the area of a triangle.
A = (1/2)(9)(4) = 18 . . . . square units
Since the result of this calculation is 18 square units, we know it has the correct area.
_____
The area measuring tool in the drawing app also shows the area to be 18.