body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

Big Ideas Math Geometry, 2014

BI

Big Ideas Math Geometry, 2014 View details

Quiz

Continue to next subchapter

Exercise 16 Page 198

A 180^(∘) rotation counterclockwise about the origin will change the coordinates of the vertices such that (a,b)→ (- a, - b).

Practice makes perfect

Let's start by looking at the given polygon.

When a figure is rotated 180^(∘) counterclockwise about the origin, the coordinates of the image's vertices will change in the following way.

(a,b)→ (- a,- b) Using this rule and the vertices of the polygon, we can find the x- and y-coordinates of the image's vertices.

Quadrilateral HIJK	(a,b)	(- a, - b)
H	(- 4,1)	(4,- 1)
I	(-2,2)	(2,-2)
J	(- 1,- 2)	(1,2)
K	(-4, - 4)	(4,4)

Knowing the vertices of quadrilateral H'I'J'K', we can draw the image.