Presentation on theme: "Properties of Special Triangles Objective: Write conjectures about isosceles triangles."— Presentation transcript:
Properties of Special Triangles Objective: Write conjectures about isosceles triangles
Vertex angle Isosceles Triangle base Base angles legs
Construct an Isosceles Triangle 1.Draw an angle, label it C 2.Mark congruent segments along each side. Label A and B 3.Connect A and B 4.Measure and label base angles. 5.Is there a pattern? C A B Base angles Isosceles Triangle Conjecture If a triangle is isosceles, then ________________________ its base angles are congruent.
Does this conjecture apply to an equilateral triangle? All isosceles conjectures apply to equilateral triangles
Is the converse true? Converse of the Isosceles Triangle Conjecture If a triangle has two congruent angles, then ___________________________ it is an isosceles triangle. 1. Draw a segment and label AB 2. Draw an acute angle at point A 3. Copy at point B. 4. Label point of intersection C 5. Measure AC and BC AB C
Find the following: Example Pg 206 #1-7, 10, 11 BD E 42 0 C A cm 3 cm