Geometry Worksheet: Understanding Angles and Triangles

An angle that measures less than 90 degrees is called an _____________ angle.

• acute

• obtuse

• right

• straight

A triangle with one angle measuring 90 degrees is a _____________ triangle.

• right

• acute

• obtuse

• scalene

Lines that will never meet, no matter how long they are extended, are called _____________ lines.

• parallel

• perpendicular

• intersecting

• curved

The point where two lines or line segments meet is called a _____________.

• vertex

• angle

• edge

• intersection

A tool used to measure angles in degrees is called a _____________.

• protractor

• ruler

• compass

• calculator

What is an angle called if it measures exactly 90 degrees?

• Acute angle

• Right angle

• Obtuse angle

• Straight angle

Which of the following is a triangle with all angles less than 90 degrees?

• Right triangle

• Obtuse triangle

• Acute triangle

• Equilateral triangle

Lines that cross each other at any angle other than 90 degrees are called:

• Parallel lines

• Perpendicular lines

• Intersecting lines

• Skew lines

Which shape has a line of symmetry?

• Circle

• Triangle

• Rectangle

• All of the above

A line with one endpoint that extends infinitely in one direction is called a:

• Line

• Line segment

• Ray

• Angle