Isosceles
2x = 180 - 60
x = 60
2x + 30 = 60
x = 15
A line that divides a figure into two equal reflections of each other.
Line of symmetry
6/x = 4/20
x = 30
All 3 sides of a triangle are the same as all 3 sides of another
SSS
7cm + 7cm +base =28cm
Base = 2
A triangle with 3 acute angles
acute triangle
A theorem stating that if two triangles are congruent, then so are all corresponding parts.
CPCTC
Some similar figures are congruent.
True or False
True
2 angles and the not included side are the same as 2 angles and the not included side of another.
AAS
5x + 40 = 180
x = 28
Part of a line that connects two endpoints
line segment
Have the exact same length
Congruent Sides
ABC~DEF
AB corresponds to DF
True or Fasle
False
Two sides and the included angle of a triangle are the same as 2 sides and the included angle of another
SAS
2x + 64 = 180
x = 58
5n = 60
n = 12
For an angle, the vertex is where the two rays meet.
Vertex of an Angle.
DFE~TSU
Point D corresponds to
Point T
2 angles and the included side of a triangle are the same as 2 angles and the included side of another.
ASA
2x + 39 = 180
x = 70.5
If a triangle is equilateral, then it is equiangular.
Equilateral Triangle Corollary
Two sides that are situated the same way in different objects.
Corresponding Sides
GHI~QRS
Segment GH corresponds to
Segment QR
Must have at least one side congruent.
Not Congruent (AA)