CK-12 Geometry Concepts

3.2. Perpendicular Lines http://www.ck12.org

Guided Practice

1. Isl⊥m? Explain why or why not.


2. Find the value ofx.


3. Find the value ofx.

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 ◦.

Practice

Find the measure of^6 1 for each problem below.

1.

2.

3.

4.

5.

6.

7.

8.

9.

In questions 10-13, determine ifl⊥m.

10.

11.

12.

13.

Find the value ofx.

14.

15.

16.

17.