Question

(02.05 MC)

Two similar triangles are shown on the coordinate grid:

Which set of transformations has been performed on triangle ABC to form triangle A'B'C'?

Dilation by a scale factor of 4 followed by reflection about the x-axis
Dilation by a scale factor of 2 followed by reflection about the x-axis
Dilation by a scale factor of 4 followed by reflection about the y-axis
Dilation by a scale factor of 2 followed by reflection about the y-axis

Answer 1

Dilation by a scale factor of 2 followed by reflection about the x-axis

Answer 2

Dilation by a scale factor of 2 followed by reflection about the x-axis

Explanation:

To answer it and view it properly let's do it by parts.

1) A closer look at the Triangle ABC shows us the coordinate points A(-2,-1) B(0,0) and C(1,-3).

2) Reflection across the x-axis gives us this triangle: A'(-2,1) B'(0,0) and C'(1,3). Notice that all y-coordinates have an opposite sign. This is a natural characteristic of a Reflection: an opposed sign of one Coordinate.

3) Finally, To Dilate a Triangle is to transform it so that it gets bigger than its original size.

If we compare the triangle with points A''(-4,2) B"(0,0) and C"(2,6) to A'(-2,1) B'(0,0) C'(1,3). Each coordinate is multiplied by 2.

Dilation by a scale factor of 2 followed by reflection about the x-axis