Isosceles Base Angles Theorem Proof

For isosceles triangles, when we are given that two sides are congruent we can prove that ______________________.

• two angles are congruent

• the third side is congruent

• three angles are congruent

• no other relationships exist

Tags

CCSS.8.G.A.2

When we are given two angles of a triangle are congruent, we can prove ____________________.

• three sides are congruent

• two sides are congruent

• three angles are congruent

• no other relationships exist

Tags

CCSS.8.G.A.5

In order to prove relationships in an isosceles triangle, we must __________________________.

• use AAS to prove it is congruent to another triangle

• split the triangle into one acute and one obtuse triangle

• divide the triangle into two right triangles

• use two angle bisectors

Tags

CCSS.HSG.CO.C.9

Fill in statement #3.

• $\overline{AC}\ \cong\ \overline{AC}$

• $\overline{AC}\ \cong\ \overline{CA}$

• $\angle BAC\cong\angle DAC$

• $\angle B\cong\angle D$

Tags

CCSS.HSG.SRT.B.5

Fill in reason #3.

• Symmetric Property

• CPCTC

• Transitive Property

• Reflexive Property

Tags

CCSS.HSG.SRT.B.5

Fill in statement #4.

• $\Delta ABC\cong\Delta ADC$

• $\Delta ABC\cong\Delta ACD$

• $\Delta BAC\cong\Delta ADC$

• $\angle B\cong\angle D$

Tags

CCSS.HSG.SRT.B.5

Fill in reason #4.

• ASA

• HL

• SSA

• SAS

Tags

CCSS.HSG.SRT.B.5

Fill in reason #5.

• Prove

• Base angles of an isosceles triangle are congruent.

• CPCTC

• definition of angle bisector

Tags

CCSS.HSG.SRT.B.5