Big Ideas Math Geometry, 2014
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Big Ideas Math Geometry, 2014 View details
4. Perimeter and Area in the Coordinate Plane
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Exercise 8 Page 34

Use the Ruler Postulate.

16 units

Practice makes perfect

To determine the perimeter of the polygon, we must find the sum of its side lengths. This polygon has four vertices, so it's a quadrilateral. Let's draw it in a coordinate plane.

We can see that the given figure is a square. Therefore, all the sides have equal lengths. QR = RS = ST = TQThe perimeter of a square can be expressed as shown below. P=4s In this formula s is the length of the side of the square. We can substitute the length of any of the four sides of the given square for s. Let's use QR. P=4QR This means that we only have to find the length of QR. We can use the Ruler Postulate to do this.
QR=|x_2 - x_1 |
QR=| 1-( - 3)|
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Simplify right-hand side
QR=|1+3|
QR=|4|
QR=4
Now, let's calculate the square's perimeter. We do so by substituting the value into the formula.
P=4QR
P=4( 4)
P=16
The square's perimeter is 16 units.