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.

   △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
4. 3.

   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)
5. 4.

   Coordinate grid, all four quadrants. The slide is not drawn. Ari flips △ABC across the y-axis, then slides it. A is (2, 5) and its image A′ is (-6, 2). What slide was used? Write it as (right, up), like (7, -3).

   (-4, -3)

6. Use this

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

7. 5.

   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)
8. 6.

   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)

9. Use this

   Coordinate grid, all four quadrants, 20 squares across. The sticker's corner A(1, 3) and its image A′(9, 3) are marked. The mirror line is not drawn.

10. 7.

    Noah flips a sticker across a vertical mirror line. Corner A(1, 3) lands on A′(9, 3). What is the mirror line? Write it like x = 2.

    x = 5

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