172k views
1 vote
Find the degree of B

Find the degree of B-example-1
User Viviana
by
7.6k points

1 Answer

4 votes

Given are the two triangles ΔADC and ΔABC.

Given are the angles, ∡DAC = 32° and ∡DCA = 41°.

In triangle ΔADC, ∡ADC + ∡DAC + ∡DCA = 180°

∡ADC + 32° + 41° = 180°

∡ADC + 73° = 180°

∡ADC = 180° - 73°

∡ADC = 107°

Now Comparing two triangles ΔADC and ΔABC;

1. AD = AB (given in the diagram)

2. DC = BC (given in the diagram)

3. AC = AC (reflexive property)

⇒ ΔADC ≡ ΔABC (Side-Side-Side congruence)

⇒ ∡ADC = ∡ABC (CPCTC: corresponding parts of congruent triangles are congruent)

∵ ∡ADC = 107° (from triangle ΔADC)

∡ABC = 107° is the final answer.

User MaxChinni
by
7.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories