Question

Part I: Angle Sum Relationships

Arrange the three congruent triangles so that angles 1 and 3 are adjacent to one another, and angle 2 is adjacent to angles 1 and 3.

B. What do you notice about the three angles?

C. What do they appear to form?

D. What can you conclude about the sum of the angles in a triangle?

Answer 1

The three angles are adjacent to each other.
They appear to form a straight line.
It means that the sum of the three angles of a triangle is appears to be 180 degrees.

Answer 2

Answer with explanation:

→→The three Angles form a Linear pair.That is

⇒∠1+∠2+∠3=180°

→→When these three congruent triangles are joined they form a Trapezoid.

→→Sum of angles in a trangle is given by Angle sum property Axiom of triangle which states that sum of the angles in a triangle is 180°.