Question

ABCD is a parallelogram. What are the measures of angles B and C? b=(3n+20) D= (6n-25)

Answer 1

Answer:

B = 65

C = 115

Step-by-step explanation:

Givens

ABCD is a parallelogram

It is lettered in such a way that B is opposite D

B = 3n+20

D = 6n-25

Solution

<B = <D                      Property of Parallelogram

3n + 20 = 6n - 25      Add 25 to both sides

3n + 20 + 25 = 6n      Combine

3n +45 = 6n                Subtract 3n from both sides

3n +45 = 6n-3n           Combine

45 = 3n                        Divide by 3

45/3=3n/3                    

n = 15                            Value of n    

B = 3n + 20                  Find B. Let n = 15

B= 3*15+20                   Combine

B = 45 + 20                 Combine

B = 65                                

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B and C are supplementary. They add up to 180

B + C = 180

65 + C = 180

C = 180-65

C = 115