Lesson on Math

Angles, Perpendicular and Parallel Lines

Math 4.6A

Parallel Lines

Straight lines that never meet.

Perpendicular Lines

Two lines that meet or intersect each other at right angles (90°).

Acute angles

Measure less than 90 degrees

Obtuse Angles

Measure more than 90 degrees

Right Angles

Measure exactly 90 degrees

Now let's answer some questions!

Choose the best answer for each.

Multiple Choice

Which pair of line segments appear to be parallel?

• AB and CD

• AG and CD

• AC and GD

• DE and BC

• none of these

Multiple Choice

Which pair of line segments appear to be perpendicular?

• AB and CD

• FE and DE

• AG and GF

• AB and AG

• none of these

Multiple Choice

Which pair of line segments appear to be parallel?

• AG and DE

• AB and GF

• BC and CD

• FE and BC

• all of these

Multiple Choice

Which pair of line segments appear to be perpendicular?

• AB and BC

• FE and CD

• CD and DE

• BC and CD

• all of these

Multiple Choice

Which pair of line segments appear to be parallel?

• AB and GF

• AG and CD

• ED and BC

• FE and ED

• none of these

Multiple Choice

Which angle is an obtuse angle?

• ∠ CDE

• ∠ BCD

• ∠ AGF

• ∠ FED

• all of these

Multiple Choice

Which angle is an acute angle?

• ∠ BCD

• ∠ CDE

• ∠ FED

• ∠ AGF

• none of these

Multiple Choice

Which angle appears to be a right angle?

• ∠ GFE

• ∠ AGF

• ∠ EDC

• ∠ BCD

• all of these

Multiple Choice

Which angle is an acute angle?

• ∠ GAB

• ∠ BCD

• ∠ CDE

• ∠ GFE

• all of these

Multiple Choice

Which angle is an obtuse angle?

• ∠ EDC

• ∠ GFE

• ∠ BAG

• ∠ ABC

• none of these