Geometry: Triangles Flashcards
The TRIANGLE INEQUALITY THEOREM states that the sum of the length of any two sides of a triangle is…
…greater than the length of the third side
In any triangle, the sum of the interior angles of a triangle is…
180 degrees
The EXTERIOR ANGLE THEOREM states that the measure of the exterior angle of a triangle is equal to the sum of…
…two remote interior angles
TIP: the remote interior angles are the two angles which aren’t adjacent to the exterior angle
SIMILAR TRIANGLES have the same shape but not…
…necessarily the same size
In SIMILAR TRIANGLES, each corresponding pair of angles has… …and the ratios of corresponding sides are…
…the same measure…
…proportional
AB/DE = BC/EF = CA/FD
the first CONDITION FOR SIMILARITY (AAA) states that…
All corresponding angles are equal
the second CONDITION FOR SIMILARITY (SSS) states that…
All corresponding sides are proportional
the third CONDITION FOR SIMILARITY (SAS) states that…
Two pairs of proportional corresponding sides with equal included angles are necessary
The first CONDITION FOR CONGRUENCE (SSS) is…
All corresponding sides are congruent
The second CONDITION FOR CONGRUENCE (SAS) is…
Two pairs of corresponding sides are congruent and the angle included between these two sides are congruent
The third CONDITION FOR CONGRUENCE (ASA) is…
Two pairs of corresponding angles are congruent and the side included between these two angles are congruent
The fourth CONDITION FOR CONGRUENCE (AAS) is…
Two pairs of corresponding angles are congruent and a side which is not included between these two angles are congruent
The TRIANGLE PROPORTIONALITY THEOREM states that if AE||BD then…
BC/AB = CD/DE
An ISOSCELES TRIANGLE has at least… …congruent sides
2
An EQUILATERAL TRIANGLE has… congruent sides and… congruent angles of… …each
3
3
60 degrees
