Sequences of transformations, including glide reflections

Answer Key - Grade 10 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. Read this first

   Use this

   △ABC and its image △A′B′C′ on a grid. AB is marked (3x + 1) cm; A′B′ is marked (2x + 6) cm.

2. 1.

   Jun reflects △ABC across the y-axis, then slides it to make △A′B′C′. AB = (3x + 1) cm and A′B′ = (2x + 6) cm. How long is AB, in cm?

   16
3. 2.

   Kira flips △ABC across the x-axis, then slides it to make △A′B′C′. ∠B = (6x − 4)° and ∠B′ = (4x + 12)°. How many degrees is ∠B?

   44

4. Use this

   △ABC and its image △A′B′C′ on a grid. AB is marked (4x − 3) cm; A′B′ is marked (2x + 11) cm.

5. 3.

   Luz turns △ABC 90° about the origin, then slides it to make △A′B′C′. AB = (4x − 3) cm and A′B′ = (2x + 11) cm. How long is AB, in cm?

   25
6. 4.

   △ABC and its image △A′B′C′ on a grid. ∠B is marked (7x + 3)°; ∠B′ is marked (4x + 30)°. Milo flips △ABC across the line y = x, then slides it to make △A′B′C′. ∠B = (7x + 3)° and ∠B′ = (4x + 30)°. How many degrees is ∠B?

   66
7. 5.

   The slide is not drawn. Zee flips △ABC across the x-axis, then slides it. A is (3, 4) and its image A′ is (7, -1). What slide was used? Write it as (right, up), like (7, -3).

   (4, 3)

8. Use this

   Coordinate grid, all four quadrants, 20 squares across. The slide is not drawn.

9. 6.

   Bo turns △ABC 90° counterclockwise about the origin, then slides it. A is (4, 1) and its image A′ is (1, 8). What slide was used? Write it as (right, up), like (7, -3).

   (2, 4)
10. 7.

    Esme flips △ABC across the line y = x, then slides it. A is (1, 6) and its image A′ is (3, -2). What slide was used? Write it as (right, up), like (7, -3).

    (-3, -3)

11. Use this

    Coordinate grid, all four quadrants, 20 squares across. The mirror line is not drawn.

12. 8.

    Pia flips a sticker across a vertical mirror line. Corner A(-5, 2) lands on A′(3, 2). What is the mirror line? Write it like x = 2.

    x = -1
13. 9.

    Ren flips a sticker across a horizontal mirror line. Corner A(4, 1) lands on A′(4, 9). What is the mirror line? Write it like y = 2.

    y = 5
14. 10.

    Coordinate grid, all four quadrants, 20 squares across. Tala flips a sticker across a horizontal mirror line. Corner A(-2, -7) lands on A′(-2, 3). What is the mirror line? Write it like y = 2.

    y = -2