Question

Item 9 Describe a similarity transformation that maps △ABC to △RST. A(3,−2), B(0, 4), C(−1,−3) and R(−4,−6), S(8, 0), T(−6, 2)

Answer 1

9514 1404 393

Answer:

Rotation 90° CW and dilation by a factor of 2 (in either order)

Explanation:

Point B has moved from the y-axis to point S on the x-axis. Its coordinate value has increased by a factor of 2. The transformation that does that is ...

• rotation 90° CW about the origin
• dilation by a factor of 2 about the origin

These transformations can occur in either order.

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In the attached, the rotation is shown first, with the purple triangle being a 90° CW rotation of the red triangle (∆ABC). The blue triangle (∆RST) is a dilation of the purple one by a factor of 2.