Question

If points $B(–3,3),E(–3,–2)$, and $D(2,–2)$ are joined on a Cartesian plane, what will the area of the figure enclosed by these points be?

• A. 10 sq units
• B. 12.5 sq units
• C. 5 sq units
• D. 25 sq units

Answer 1

The correct option is B 12.5 sq units

Let’s plot points $B(–3,3),E(–3,–2)$, and $D(2,–2)$ on the coordinate plane. When we join points BDE, we see the figure shown below.


The shape formed is a right triangle with the right angle at E.
Length of EB = 5 units (if we count blocks from point E to point B)
Length of ED = 5 units (if we count blocks from point E to point D)
Area of triangle $BED=\frac{1}{2}\times \text{base}\times \text{height}$
$=\frac{1}{2}\times 5\times 5$
$=\frac{25}{2}=12.5\text{sq units}$