Download Angle Relationships

Angle Relationships
By Mr. Q
Adjacent Angles
• Two angles with common vertex
• Have common sides
• Interior angles do not overlap
Supplementary Angles
• Two angles whose measures equal 180
degrees
45 degrees
??
Vertical Angles
• Also called opposite angles
• When two lines intersect, the opposite angles
are equal
• <1 = <3
• <2 = <4
1 2 3
4
Polygon
• Can be divided into triangles
• Sum of interior angles in a triangle = 180 d
• To find the sum of the measures of all angles
in a polygon:
• Multiply the number of triangles by 180°
Steps to find the sum of the angles in a
polygon
1. Draw polygon (geometry template)
2. Divide polygon into triangles
3. Multiply the number of triangles by 180°
Rule
• Number of sides a polygon has MINUS 2 = the
number of triangles it can be divided into
• Example: Square
 4 sides – 2 = 2 triangles
 2 * 180° = 360°
Table
Polygon
Number of sides
Number of sides –2
is the number of
triangles that can
be made
Number of
triangles * 180 is
the sum of the
angles for this
polygon
Triangle
3
3-2 = 1
1 * 180 = 180
Quadrangle
4
4-2 = 2
2 * 180 = 360
Pentagon
5
5-2=3
3 * 180 = 540
Hexagon
6
6-2=4
4 * 180 = 720
Transversal
• A line that crosses two lines
• Any two angles formed by the line and
transversal are:
• Vertical or supplementary angles