# Reflections in a Coordinate Plane (Student Copy)

1. Draw a triangle with vertices at A(-3, 3) B(-2, -1), and C(-1,4). a. Reflect ABC over the y-axis to form A'B'C'

b. List the coordinates of A'B'C'. When reflecting a point over the y-axis , which coordinate remains the same? Which coordinates change? A(-3,3) A'(?,?) B(-2,-1) B'(?,?) C(-1,4) C'(?,?)

c. Write an algebraic notation to show the rule for reflecting a figure over the y-axis. (x, y) (?,?)

d. Find the side lengths and area measures of the two triangles. What do you observe?

2. Draw a triangle with vertices at A(-3, 3) B(-2, -1), and C(-1,4). a. Reflect ABC over the x-axis to form A'B'C'

b. List the coordinates of A'B'C'. When reflecting a point over the x-axis , which coordinate remains the same? Which coordinates change? A(-3,3) A'(?,?) B(-2,-1) B'(?,?) C(-1,4) C'(?,?)

c. Write an algebraic notation to show the rule for reflecting a figure over the x-axis.

d. Find the side lengths and area measures of the two triangles. What do you observe?

## Practice

Without graphing, find the coordinates of the reflected image.

## 3.

ABC with vertices A(5, 1), B(1, 2), and C(6, 2). Reflected over the x-axis. A(5, 1) A'(?, ?) B(1, 2) B'(?, ?) C(6, 2) C'(?, ?)

## 4.

KLM with vertices K(2, 3), L(5, 1), and M(4, -2). Reflected over the y-axis. K(2, 3) K'(?, ?) L(5, 1) L'(?,?) M(4, -2) M'(?, ?)