Draw the polygon. What do you need to know to be able to calculate its area?
7.5 square units
Practice makes perfect
When drawing the polygon, the first thing we should notice is its shape. This polygon has three vertices, so it's a triangle. Let's draw it in a coordinate plane.
We can see that it is a right triangle. To calculate its area, we can use the formula for the area of a triangle.
A=1/2bh
In this formula, b is the length of the base of the triangle and h is the height of the triangle. The base of this triangle is the side GF. The height is the side EF. We can find the length of the base using the Ruler Postulate with the x-coordinates.
GF=|3-(- 2)|=5
Thus, b= 5. The height can be found by using the Ruler Postulate with the y-coordinates.
EF=|- 2-1|=3
Therefore, h= 3. Now we are ready to calculate the area of the triangle.
