After a rotation of 90° about the origin, the coordinates of the vertices of the image of a triangle are A'(5, 3), B'(–2, 1), and

After a rotation of 90° about the origin, the coordinates of the vertices of the image of a triangle are A'(5, 3), B'(–2, 1), and C'(1, 7). What are the coordinates of the vertices of the pre-image?

A –

B –

C –

1 thought on “After a rotation of 90° about the origin, the coordinates of the vertices of the image of a triangle are A'(5, 3), B'(–2, 1), and”

  1. The coordinates of the vertices of the preimages are A ( 3, 5) , B ( 1, 2) and C ( 7, -1)

    How to determine the coordinates

    It is important to note the following about the 90 degrees rotation about the origin
    • A( x ,y ) becomes A’ ( -y,  x )
    • switch x and y and make y negative
    Note that
    A ( x, y) is the coordinates of the preimage
    A’ ( -y , x) is the coordinates after the said rotation about the origin
    Converting the transformed coordinates to the preimage coordinates
    For vertex A
    A’ ( 5, 3)
    Compare with A’ ( -y, x)
    x = 3
    y = -5
    Substitute the values
    A ( 3, 5 )
    For vertex B
    B’ ( -2, 1)
    Compare with B’ ( -y, x)
    x = 1
    y = 2
    Substitute the values
    B ( 1, 2)
    For vertex C
    C’ ( 1, 7)
    Compare with C’ ( -y, x)
    x = 7
    y = -1
    Substitute the values
    C ( 7, -1)
    Thus, the coordinates of the vertices of the preimages are A ( 3, 5) , B ( 1, 2) and C ( 7, -1)
    Learn more about transformation here:
    #SPJ1

    Reply

Leave a Comment