1. Triangles & angles

2. Algebra Section 3-4
Supplementary angles - Two angles are supplementary if the sum of their measure is 180.
Complementary angles - Two angles are complementary if the sum of their measure is 90.
Sum of the angles of a triangle - The sum of the measures of the angles in any triangle is 180.

3. Section 3-4 definitions cont.
Triangle - a polygon with tree sides and three angles.
Equilateral Triangle - each angle’s measure is the same.
Isosceles Triangle - at least two of the angles have the same measurement.
Right triangle - has one angle that is 90 degrees.

4. Section 3-4 Examples
The measure of an angle is three times the measure of its supplement. Find the measure of each angle.
X +3x = 180
4x = 180
4x/4 = 180/4 ( divide both sides by 4)
x = 45
Thus the measures are 45 and 3 x 45 or 135

5. Section 3-4 Examples
The measure of an angle is 34 greater than its complement. Find the measure of each angle.
x + (x + 34) = 90
2x + 34 = 90
2x = (subtract 34 from both sides)
2x = 56
2x/2 = 56/2 ( divide both sides by 2)
x = 28
The measures are 28 and ( ) or 62