Exercise 17 Page 410

When drawing the polygon, the first thing we should notice is its shape. This polygon has four vertices, so it is a quadrilateral. Let's draw it in a coordinate plane.

Notice that the sides of the quadrilateral are vertical lines and that the top and bottom are horizontal lines. Vertical and a horizontal lines are perpendicular to each other. This means that all of the angles in the polygon are right angles and that the quadrilateral is a rectangle. We can calculate its area using the formula for the area of a rectangle. A=l w In this formula, l is the length and w is the width. We can find the measure of the length and width using the Ruler Postulate. Let's start with WX.

The length is 3 units. We will now find the width in the same way.

The width is 3 units. Since the dimensions are equal, the quadrilateral is a square. We can now calculate its area. A=l w ⇒ 3* 3=9 square units