Triangle Congruence
by Jeimar Buitrago
1. Congruence and Transformation
1.1. Dilation - stretches or shrinks the original figure
1.2. Isometry - A linear transformation which preserves length
1.3. Rigid Transformation - transformation of the plane that preserves length, reflection, translation, rotation.
2. Classifying
2.1. Acute Triangle - less than 90 degree angle
2.2. Equiangular triangle - interior angles are equal in measure
2.3. Right Triangle - an angle which is 90 degree
2.4. Obtuse triangle - more then 90 degree
2.5. Equilateral Triangle - is a triangle in which all three sides are equal.
2.6. isosceles triangle - having not just two, but all three sides and angles equal.
2.7. scalene triangle - that has three unequal sides, such as those illustrated above
3. Angle relationship in triangles
3.1. Auxiliary Line - is an extra line needed to complete a proof in plane geometry
3.2. Corollary - statement is that an equilateral triangle is also equiangular.
3.3. Interior -
3.4. Exterior
3.5. Interior angle - the angle between adjacent sides of a rectilinear figure.
3.6. Exterior angle - the angle between a side of a rectilinear figure and an adjacent side extended outward.
3.7. Remote interior angle -
4. Congruent Triangle
4.1. Corresponding angle - the angles that occupy the same relative position at each intersection where a straight line crosses two others.
4.2. Corresponding sides - pair of matching angles or sides that are in the same spot in two different shapes.
4.3. Corresponding polygons - All the angles in a rectangle are congruent to each other and now check that the sides are proportional to each other.
5. Triangle congruence: SSS and SAS
5.1. Triangle rigidity - A property of triangles that states that if the side lengths of a triangle are fixed, the triangle can have only one shape
5.2. Included angle - s the angle between two sides of a triangle. It can be any angle of the triangle, depending on its purpose
6. Triangle congruence: ASA, AAS, and HL
6.1. Included sides - The common leg of two angles