Angles Of A Triangle
The angles of a triangle have the following properties:
Property 1: The sum of the 3 angles in a triangle is always 180˚.
Example :
Property 2 . The sum of an interior angle and its adjacent exterior angle is 180˚.
Example :

Property 3 . An exterior angle of a triangle is equal to the sum of the two opposite interior angles.
Example :

Property 4 . Also, recall that an equilateral triangle has 3 equal angles that are 60˚ each. An isosceles triangle has 2 equal angles, which are the angles opposite the 2 equal sides
The above angle properties would enable us to find unknown angles.
Example:
Find the value of x in the following triangle.

Solution:
x + 24˚ + 32˚ = 180˚ (sum of angles is 180˚)
x + 56˚ = 180˚
x = 180˚ – 56˚
= 124˚
Example :
Find the values of x and y in the following triangle.

Solution:
x + 50˚ = 92˚ (sum of opposite interior angles = exterior angle)
x = 92˚ – 50˚
= 42˚
y + 92˚ = 180˚ (interior angle + adjacent exterior angle = 180˚.)
y = 180˚ – 92˚
= 88˚
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