Back to Angles are taken to angles of the same measure — Problem 1 · Task Set 20

Exercises: Rigid Motions Preserve Angle Measure

Work through each section in order. A rigid motion is a translation, reflection, or rotation. For each problem, decide what the angle-preservation property tells you before measuring or computing. Show your work where indicated.

Grade 8·21 problems·~30 min·Common Core Math - Grade 8·standard·8-g-a-1b

Work through problems with immediate feedback

Fluency Practice

Apply each transformation and verify the angle-preservation property. Use the measure of the original angle to predict the measure of the image.

$A coordinate grid showing a 55-degree angle and its translated image angle of the same shape.$

Angle $ABC$ measures $55\degree$ . It is translated by the rule $(x, y) \rightarrow (x + 4, y + 3)$ to form image angle $A'B'C'$ . What is the measure of the image angle?

$55\degree$

$59\degree$ , because the translation adds to the measure.

$62\degree$ , because both shifts add to the measure.

It cannot be determined without measuring.