Geometry Angle relationships Vocabulary
right angle
90 degrees
perpendicular lines
Lines that intersect to form right angles
Adjacent angles
angles that are next to eachother
Sum of all angles in a polygon
The number of sides minus 2 times 180 S=(n-2)180
transversal cuts parallel
a line that intersects two or more lines, 8 angles formed
alternate exterior angles
angles that are on opposite (alternate) sides of the transversal and are on the OUTSIDE (or exterior) of the parallel lines. They are EQUAL
alternate interior angles
angles that are on opposite (or alternate) sides of the transversal and are on the INSIDE (or interior) of the parallel lines. They are EQUAL
corresponding angles
angles that share the same position on 2 parallel lines that are cut by the same transversal
congruent angles in a transversal
angles with the same measure
obtuse angle
greater than 90 degrees
acute angle
less than 90 degrees
parallel line
lines in the same plane that never intersect
Vertical angles
opposite angles that have the same measure, the share a vertex
Angles in a triangle
the sum is 180 degrees a+b+c=180
Exterior angle measure of a triangle
the sum of the measures of the 2 non-adjacent interior angles
Supplementary angles
two angles with the sum of 180 degrees, make a linear pair (next to each other)
Complimentary angles
two angles with the sum of 90 degrees
Prove Congruency
1) Vertical Angles 2) Corresponding Angles 3) Alternate Interior Angles 4) Alternate Exterior Angles
Tools to help find angle measures
Supplementary angles ( angles on a straight line adding up to 180)
vertex
The common endpoint of an angle