Question

4.6 understand: similar figures
when a triangle is dilated and transformed, what remains unchanged?
the lengths of the sides
the area of the triangle
the color of the triangle
the angles of the triangle

Explanation:

When a triangle is dilated (scaled) and transformed (moved via translation, rotation, reflection), the angles remain unchanged. Dilation changes side lengths proportionally (so lengths of sides change), area is scaled by the square of the dilation factor (so area changes), and perimeter is scaled by the dilation factor (so perimeter changes). But angle measures are preserved in similar figures (which a dilated triangle is similar to the original).

Answer:

The angles of the triangle.