How to Write a Proof for Congruent Triangles Using SAS

The video tutorial explains how to prove triangle congruence using given information and the side-angle-side (SAS) theorem. It emphasizes the importance of identifying given congruences and angles, and how to calculate missing angles in triangles. The tutorial concludes with a proof of congruence using the third angle theorem.

What is the first step in proving triangle congruence?

• Identify the unknowns

• Draw the triangles

• Calculate the angles

• Write down the given information

Which of the following is a given congruence in the problem?

• Angle P is congruent to angle F

• Side PR is congruent to side DF

• Angle R is congruent to angle E

• Side PT is congruent to side DE

Why is the included angle important in the side-angle-side theorem?

• It is the largest angle in the triangle

• It is always 90 degrees

• It must be between the two known sides

• It determines the length of the sides

What can be concluded if two angles of a triangle are known?

• The triangle is right-angled

• The third angle can be determined

• The triangle is equilateral

• The triangle is isosceles

If two angles in two triangles are equal, what can be inferred about the third angle?

• The third angle is smaller

• The third angle is different

• The third angle is equal

• The third angle is larger

What is the sum of all angles in a triangle?

• 90 degrees

• 180 degrees

• 360 degrees

• 270 degrees

What theorem is used to conclude that triangle PRT is congruent to triangle DEF?

• Side-Side-Side

• Angle-Side-Angle

• Angle-Angle-Angle

• Side-Angle-Side