Quiz – Exterior Angle Theorem of a Triangle

Test your understanding of the Exterior Angle Theorem.

Try to answer the questions before checking the answers at the bottom of the page.

Question 1

Remote interior angles are \(50^\circ\) and \(40^\circ\).

Find the exterior angle.

A) \(80^\circ\)
B) \(90^\circ\)
C) \(100^\circ\)

Question 2

Exterior angle \(= 70^\circ\)
One interior angle \(= 30^\circ\)

Find the other interior angle.

A) \(30^\circ\)
B) \(40^\circ\)
C) \(50^\circ\)

Question 3

Exterior angle \(= 100^\circ\)
Remote interior angles are \(x\) and \(x\)

Find \(x\).

A) \(40^\circ\)
B) \(50^\circ\)
C) \(60^\circ\)

Question 4

Exterior angle \(= 120^\circ\)
Remote interior angles are \(2x\) and \(x\)

Find \(x\).

A) \(30^\circ\)
B) \(40^\circ\)
C) \(60^\circ\)

Question 5

Exterior angle \(= 90^\circ\)
One remote interior angle \(= 20^\circ\)

Find the other angle.

A) \(50^\circ\)
B) \(60^\circ\)
C) \(70^\circ\)

Question 6

Which angles are called the remote interior angles?

A) The exterior angle and the angle beside it
B) The two angles outside the triangle
C) The two interior angles not next to the exterior angle

Question 7

An exterior angle is \(135^\circ\).

One remote interior angle is \(55^\circ\).

Find the other remote interior angle.

A) \(80^\circ\)
B) \(90^\circ\)
C) \(100^\circ\)

Question 8

An exterior angle is \(5x\).

The two remote interior angles are:

\(2x+10^\circ\)

and

\(x+20^\circ\)

Find \(x\).

A) \(10\)
B) \(15\)
C) \(20\)

Question 9

An exterior angle is \(100^\circ\).

The two remote interior angles are:

\(x+10^\circ\)

and

\(2x\)

Find \(x\).

A) \(20^\circ\)
B) \(25^\circ\)
C) \(30^\circ\)

Question 10

An exterior angle is \(110^\circ\).

One remote interior angle is \(45^\circ\).

Find the other remote interior angle.

A) \(65^\circ\)
B) \(75^\circ\)
C) \(155^\circ\)

Answers

  1. B – \(90^\circ\)
  2. B – \(40^\circ\)
  3. B – \(50^\circ\)
  4. B – \(40^\circ\)
  5. C – \(70^\circ\)
  6. C – The two interior angles not next to the exterior angle
  7. A – \(80^\circ\)
  8. B – \(15\)
  9. C – \(30^\circ\)
  10. A – \(65^\circ\)

Practice

  • Take the Quiz (Current page)

Continue Learning

  1. Sum of Exterior Angles of a Triangle (Proof)
  2. Exterior Angle Theorem of a Triangle
  3. Two Exterior Angles at a Vertex are Equal (Proof)
  4. Two Exterior Angles are Equal at a Vertex (Quick Proof)

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