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Should their be an SSA Postulate?

Author:Emma Haddad

Note on All Multiple Choice!

When you enter your answer for multiple choice, it will give you the "try again?" option whether you got the answer right or wrong, so try not to let that confuse you.

Look at the diagram shown below. Which segments are congruent? Which angles are congruent?

Which congruence pattern applies to this diagram?

Select all that apply
  • A
  • B
  • C
  • D
Check my answer (3)

Can you change the length of AB?

Select all that apply
  • A
  • B
Check my answer (3)

Can you move point F?

Select all that apply
  • A
  • B
Check my answer (3)

Can you change the length of DF?

Select all that apply
  • A
  • B
Check my answer (3)

Can you change the length of BE?

Select all that apply
  • A
  • B
Check my answer (3)

What else changes when you move point E? Be specific.

What happens when you adjust the slider labeled k?

Now move point E so that it lands somewhere on the long ray extending from point A and makes a triangle.

IS CDF a triangle now? Explain.

Rotate point F so that it lands on the ray extending from point C to complete triangle CDF.

Is triangle CDF congruent to triangle ABE? Justify your answer.

Try to find another point on the ray to put point F so that it forms a different triangle. Can you do it? Explain.

Experiment with different values of k (the angle slider), lengths of BE, and positions of point F. Try to make two triangles which satisfy the SSA criteria but are NOT congruent.

Can you make two triangles satisfy the SSA criteria but are not congruent? How? List the side and angle values for each triangle.

Can you find a combination of angle measures and side lengths where the triangles do have to be congruent, i.e. there is only one possible place to put point F and it makes a triangle that is congruent to ABE? Explain how and give the side/angle measures for your triangles.

Should geometry include an SSA Postulate for triangle congruence? Justify your answer.

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