OpenUp 8th Math 1.9 Practice Problems and Vocab

___ angles are opposite angles that share the same vertex. They are formed by a pair of intersecting lines. Their angle measures are equal.

For example, angles AEC and DEB are ___ angles. If angle AEC measure 120 degrees, then angle DEB must also measure 120 degrees.

Angles AED and BEC are another pair of ___ angles.

(a)  

Select all of the parallel lines.

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Draw parallel lines AB and CD .

Pick any point E. Rotate AB 90 degrees clockwise around E.

Rotate CD 90 degrees clockwise around E.

Make mental notes of what you notice.

Select all of the perpendicular lines.

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Points P and Q are plotted on a line. Find and plot Point R so that 180-degree rotation with center R sends P to Q and Q to P.

In the picture triangle A'B'C' is an image of triangle ABC after a rotation. The center of rotation D. What is the length of side B'C'? Type the number only.

(a)  

In the picture triangle A'B'C' is an image of triangle ABC after a rotation. The center of rotation D. What is the measure of angle B? Type the number only.

(a)