EXTERIOR ANGLE PROPERTY OF A TRIANGLE

The exterior angle is equal to the sum of the two opposite interior angles.

Find a in the following, giving brief reasons :

Example 1 :

Solution :

The exterior angle is equal to the sum of the two opposite interior angles.

mA = 70°, mB = a° (interior angles)

mD = 125° (exterior angle)

mA + mB = mD

70° + a° = 125°

Subtract 70° from both sides.

a° = 55°

Example 2 :

Solution :

mA = 90°, mB = 45° (interior angles)

mD = a° (exterior angle)

mD = mA + mB

a° = 90° + 45°

a° = 135°

Example 3 :

Solution :

m ∠A = 101°, mB = 45° (interior angles)

mD = a° (exterior angle)

mD = mA + mB

a° = 101° + 45°

a =  146°

Example 4 :

Solution :

m ∠A = a°, mB = 63° (interior angles)

mD = 132° (exterior angle)

mA + mB = mD

a°  + 63° = 132°

Subtract 63° from both sides.

a° = 69°

Example 5 :

Solution :

m ∠A = a°, mB = 62° (interior angles)

mD = 117° (exterior angle)

mA + mB = mD

a° + 62° = 117°

Subtract 62° from both sides.

a° = 55°

Example 6 :

Solution :

m ∠A = 40°, mB = 90° (interior angles)

mD = a° (exterior angle)

m∠D = m∠A + m∠B

a° = 40° + 90°

a° = 130°

Kindly mail your feedback to v4formath@gmail.com

We always appreciate your feedback.

©All rights reserved. onlinemath4all.com

Recent Articles

  1. Problems on Finding Derivative of a Function

    Mar 29, 24 12:11 AM

    Problems on Finding Derivative of a Function

    Read More

  2. How to Solve Age Problems with Ratio

    Mar 28, 24 02:01 AM

    How to Solve Age Problems with Ratio

    Read More

  3. AP Calculus BC Integration of Rational Functions by Partical Fractions

    Mar 26, 24 11:25 PM

    AP Calculus BC Integration of Rational Functions by Partical Fractions (Part - 1)

    Read More