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.

Dashboard

Big Ideas Math Integrated I, 2016 View details

2. Reflections

Continue to next subchapter

Exercise 8 Page 553

Reflected points are the same distance from but on opposite sides of the line of reflection before and after the reflection takes place.

Practice makes perfect

We are given the vertices of triangle JKL. Let's start by plotting the given points and connecting them to draw our quadrilateral.

We want to graph its image after a reflection in the line y=- x. To do so, let's add the given line of reflection to the graph of △ JKL.

Now, we need to plot each vertex of the image J'K'L' the same distance from the line of reflection as its corresponding vertex on the preimage JKL.

Preimage JKL		Image J'K'L'
Vertex	Distance From the y=- x	Vertex	Distance From the y=- x
J(1,3)	2 units above the line y=- x	J'(- 3,- 1)	2 unit below the line y=- x
K(4,4)	4 units above the line y=- x	K'(- 4,- 4)	4 units below the line y=- x
L(3,1)	2 units above the line y=- x	L'(- 1,- 3)	2 units below the line y=- x

Finally, we can do the reflection by plotting the obtained points and connecting them to draw the image of triangle JKL.

Subchapter links

Communicate Your Answer p.551

Monitoring Progress p.552-555

Exercises p.556-558

Exercise 8 Page 553

Hints

Check the answer

Practice exercises

Asses your skill