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U 1, Lsn 3 Triangles


Alternate Interior Angles Theorem (Alt. Int.) If two parallel lines are cut by a transversal, then each pair of alternate interior angles are congruent
Acute Angle An angle with measure less than 90 degrees
Triangle Sum Theorem The sum of the interior angles of a triangle is 180 degrees
Vertical Angles Angles formed by two crossing lines and have equal measure, they are across from each other
Exterior Angle Angle outside the triangle and have measure equal to the two remote interior angles of the triangle
Centroid A point of concurrency inside the triangle where the three medians meet and is the balancing point of the triangle
Median A line segment that has one end point at the midpoint of a triangle side and connects to the opposite vertex
Midsegment A segment that forms when connecting the two midpoints of two sides of a triangle and has equal measure to 1/2 the parallel side
Isosceles Triangle A triangle with two sides congruent
Congruent Equal shape and size - used to describe geometric figures and concepts (like the word 'equal' is used in regular math)
Opposite Means 'Across from' in math class
Adjacent Means 'Next to'
Equilateral triangle A triangle with all sides and angles congruent
CPCTC Corresponding Parts of Congruent Triangles are Congruent
SAS If two sides and an included angle of one triangle are congruent to two sides and an included angle of another triangle, then the two triangle are congruent
SSS IF the sides of one triangle are congruent to the sides of a second triangle, then the triangles are congruent
ASA If two angles and the included side of one triangle are congruent to the two angles and included side of another triangle, then the two triangles are congruent
AAS If two angles and the non-included side of one triangle are congruent to the two angles and non-included side of another triangle, then the two triangles are congruent
Naming Angles Used when identifying an angle, the vertex comes in the middle between the two endpoints
Created by: martha.kelley
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