Looks like no one added any tags here yet for you.
Isosceles triangle
At least two congruent sides
Scalene triangle
No congruent sides of a triangle
Equilateral
3 congruent sides
Acute
All angles <90 degrees
Obtuse
One angle >90 degrees
Right
One right <
Equiangular
3 congruent <โs
Corollary
A statement easily proved with a theorem
Remote interior <โs in/outside a triangle
Exterior < is = the sum of two remote interior <โs
Corresponding parts
<โs or sides of a figure that share the same position in two SEPARATE figures (letters match to spots)
Third <โs theorem
If two <โs of one triangle are congruent to 2 <โs of another, then the 3rd <โs are congruent to each other
Corresponding parts of congruent triangles are congruent
CPCTC
Side-Angle-Side Theorem
SAS
Included <
Has to fall between the known sides
Vertex
The < that falls between the legs of an isosceles triangle
Base angles theorem
If 2 sides of a triangle of congruent, then the angles opposite of them are congruent
Converse of base angles theorem
If 2 angles of a triangle are congruent, then the sides opposite of them are congruent
Corollary to base <โs theorem
If triangle is equilateral, then it is equiangular
Corollary to converse of base <โs theorem
If triangle is equiangular, then it is equilateral
Legs
When an isosceles triangle has two congruent sides, the two congruent sides are called