Download Using Congruent Triangles: CPCTC

Using Congruent Triangles: CPCTC
Lesson 4-4
Additional Examples
Geometry
What other congruence statements can you prove from the
diagram, in which SL SR, and 1 2 are given? SC SC by the
Reflexive Property of Congruence, and LSC
RSC by SAS.
3 4 by corresponding parts of congruent triangles are congruent.
When two triangles are congruent,
you can form congruence statements
about three pairs of corresponding angles
and three pairs of corresponding sides.
List the congruence statements.
Using Congruent Triangles: CPCTC
Lesson 4-4
Geometry
Additional Examples
(continued)
Sides:
Angles:
SL
SC
CL
SR
SC
CR
Given
Reflexive Property of Congruence
Other congruence statement
1
2
Given
3
4
Corresponding Parts of
Congruent Triangles
CLS
CRS
Other congruence statement
In the proof, three congruence statements are used, and one congruence
statement is proven. That leaves two congruence statements remaining that
also can be proved:
CLS CRS
CL CR
Using Congruent Triangles: CPCTC
Lesson 4-4
Additional Examples
Geometry
The Given states that DEG and DEF are right angles.
What conditions must hold for that to be true?
DEG and DEF are the angles the officer makes with the ground.
So the officer must stand perpendicular to the ground, and the ground
must be level.