Exterior Angles of Triangles (Grade 8)

Print Test (Only the test content will print)
Name: Date:

Exterior Angles of Triangles

1. 
What is the sum of the exterior angles of a triangle?
  1. [math]180deg[/math]
  2. [math]270deg[/math]
  3. [math]360deg[/math]
  4. [math]540deg[/math]
2. 
The exterior angle of a triangle is equal to
  1. the value of its adjacent angle
  2. the sum of its opposite interior angles
  3. the product of its opposite interior angles
  4. the difference between its opposite interior angles
3. 
Which of the following statements about the exterior angle of a triangle is true?
  1. it is always equal to the value of its adjacent angle
  2. it is always larger than either opposite interior angle
  3. it is always larger than the sum of its opposite interior angles
  4. it is always equal to the sum of the interior angles of the triangle
4. 
What is the measure of one external angle of an equilateral triangle?
  1. [math]30deg[/math]
  2. [math]60deg[/math]
  3. [math]120deg[/math]
  4. [math]180deg[/math]
5. 
The measures of the angles of triangle ABC are:

[math]angA = xdeg[/math]
[math]angB = ydeg[/math]
[math]angC = zdeg[/math]

Extend side AC to the right to form an external angle. Which expression equals the value of the external angle?
Obtuse Triangle ABC v3
  1. [math]y - z[/math]
  2. [math]y + z[/math]
  3. [math]x - y[/math]
  4. [math]x + y[/math]
6. 
An external angle of a triangle is [math]80deg[/math]. Which of the following could be a value of one of its opposite interior angles?
  1. [math]50deg[/math]
  2. [math]80deg[/math]
  3. [math]100deg[/math]
  4. [math]120deg[/math]
7. 
Extend [math]bar (AC[/math] to the right of C to create an exterior angle adjacent to C. If [math]angA = 100deg[/math] and [math]angB = 25deg[/math], what is the value of the exterior angle adjacent to C?
Scalene Triangle ABC v1
  1. [math]55deg[/math]
  2. [math]75deg[/math]
  3. [math]100deg[/math]
  4. [math]125deg[/math]
8. 
Triangle ABC is isosceles and its vertex is B. If [math]angB = 30deg[/math], what is the measure of an external base angle of the triangle?
Isosceles Triangle ABC v1
  1. [math]45deg[/math]
  2. [math]75deg[/math]
  3. [math]105deg[/math]
  4. [math]150deg[/math]
9. 
The exterior base angles of an isosceles triangle each measure [math]100deg[/math]. What is the measure of the interior vertex angle of the triangle?
  1. [math]20deg[/math]
  2. [math]60deg[/math]
  3. [math]80deg[/math]
  4. [math]160deg[/math]
10. 
Extend line AC to the right and place point D on the extended line to create line ACD. Given the following:

[math]mangBCD = 115deg[/math]
[math]mangB = 90deg[/math]
[math]mangA = xdeg[/math]

Which equation can be used to solve for [math]mangA[/math]?
Acute Triangle ABC v3
  1. [math]90 + x = 115[/math]
  2. [math]65 + x = 115[/math]
  3. [math]65 - x = 115 [/math]
  4. [math]90 - x = 115[/math]

Become a Help Teaching Pro subscriber to access premium printables

Unlimited premium printables Unlimited online testing Unlimited custom tests

Learn More About Benefits and Options

You need to be a HelpTeaching.com member to access free printables.
Already a member? Log in for access.    |    Go Back To Previous Page