http://www.ck12.org Chapter 4. Triangles and Congruence
4.3 Triangle Congruence using SSS and SAS
Learning Objectives
- Use the distance formula to analyze triangles on thex−yplane.
- Apply the SSS Postulate to prove two triangles are congruent.
- Apply the SAS Postulate to prove two triangles are congruent.
Review Queue
- Determine the distance between the two points.
a. (-1, 5) and (4, 12)
b. (-6, -15) and (-3, 8) - Are the two triangles congruent? Explain why or why not.
a.AB||CD,AD||BC
AB∼=CD,AD∼=BC
b.Bis the midpoint ofACandDE- At this point in time, how many angles and sides do we have to know are congruent in order to say that two
triangles are congruent?
Know What? The “ideal” measurements in a kitchen from the sink, refrigerator and oven are as close to an
equilateral triangle as possible. Your parents are remodeling theirs to be as close to this as possible and the
measurements are in the picture at the left, below. Your neighbor’s kitchen has the measurements on the right.
Are the two triangles congruent? Why or why not?