Upload
geraldine-cunningham
View
217
Download
1
Embed Size (px)
Citation preview
Congruence and Triangles
Unit 1B2 Day 2
Tell whether it is possible to create each of the
following: acute scalene triangle obtuse equilateral triangle right isosceles triangle scalene equiangular triangle right scalene triangle
Do now
Informal: Two figures are congruent if they have exactly
the same size and shapes. Two figures are congruent if and only if their
corresponding parts are congruent. Definition of congruent triangles: all _________
pairs of corresponding sides congruent; all _________ pairs of corresponding angles congruent.
Congruence
Are the two triangles congruent? Use the
definition of congruent triangles. If so, write a congruence statement.
Ex. 1: Proving Congruence
In the diagram, NPLM ≅ EFGH. Find the
values of x and y.
Ex. 1A: Congruent Figures
If two angles of one triangle are
congruent to two angles of another triangle, then ______________________
__________________________________
Third Angles Theorem
Find the value of x.
Ex. 2: Third Angles Theorem
In the diagram, ABCD ≅ KJHL. Find the values
of x and y.
Ex. 2A
Determine whether the triangles are
congruent. Justify your reasoning.
Ex. 3: Determining Congruence
Decide whether the triangles are congruent.
Justify your reasoning.
Ex. 3A
Given: AB || DC, AB ≅ DC, E is the midpoint of
BC and AD. Prove: ΔAEB ≅ ΔDEC
Ex. 4: Proving Congruence
Reflexive property of congruent
triangles: Every triangle is congruent to ____________.
Symmetric property of congruent triangles: If ΔABC ≅ ΔDEF, then _________________
Transitive property of congruent triangles: If ΔABC ≅ ΔDEF and ΔDEF ≅ ΔJKL, then ______________.
Properties of Congruent Triangles
If ΔGHJ ≅ ΔMNP, what
corresponding angles and sides are congruent?
Closure