After rotational transformation, the measure of angle ∠A' = 40°.
What is a rotation transformation?
A rotation is a transformation that turns the figure in either a clockwise or counterclockwise direction on the coordinate plane. In both transformations the size and shape of the figure stays exactly the same.
For the given situation,
The diagram shows the two triangles.
Triangle ABC is the original triangle and A'B'C' is the triangle obtained after the rotation of -120°.
From the definition, in rotational transformation the size and shape of the figure stays exactly the same. Then the angle measures are also remains the same.
Thus the measure of angle A' is [tex]\angle A' = \angle A = 40[/tex]
Hence we can conclude that after rotational transformation, the measure of angle ∠A' = 40°.
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