Answer:
B = 65
C = 115
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