CK-12 Geometry-Concepts

http://www.ck12.org Chapter 3. Parallel and Perpendicular Lines

Answers:

1. If the two adjacent angles add up to 90◦, thenlandmare perpendicular.

23 ◦+ 67 ◦= 90 ◦. Therefore,l⊥m.

2. The two angles together make a right angle. Set up an equation and solve forx.

( 12 x− 1 )◦+( 10 x+ 3 )◦= 90 ◦sox= 4 ◦.

3. The two angles together make a right angle. Set up an equation and solve forx.

( 2 x)◦+x◦= 90 ◦sox= 30 ◦.

Interactive Practice

MEDIA

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