Algebra Section 3-4

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AlgebraSection 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.

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Section 3-4 definitions cont.

• Triangle - a polygon with three sides and three
  angles.
• Equilateral Triangle - each angles 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.

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Section 3-4Examples

• 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

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Section 3-4Examples

• 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 34 -34 90 -34 (subtract 34 from both
  sides)
• 2x 56
• 2x/2 56/2 ( divide both sides by
  2)
• x 28
• The measures are 28 and (28 34) or 62