FIRST TO ANSWER (CORRECTLY) GETS BRAINLIEST
I NEED HELP ASAP WE DIDN'T LEARN THIS :/

A. 20°

Step-by-step explanation:

ΔABC's full internal angle measurements = 180°

m∠CAB = 80°

m∠ACB = 50°

m∠DBA = 30°

m∠DBC = ?

Add the measurements of the angles together, and subtract from the total:

m∠DBC = 180 - (80 + 50 + 30)

m∠DBC = 180 - (160)

m∠DBC = 20°

A. 20° is your answer.

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∠DBC = 20°

Step-by-step explanation:

∠A + ∠C + ∠ABC = 180   { sum of all angles of triangle}

50 + 80 + ∠ABC = 180

130 +∠ABC = 180

∠ABC  = 180 - 130

∠ABC = 50°

∠ABD + ∠DBC = ∠ABC

30 + ∠DBC = 50

∠DBC = 50 - 30

∠DBC = 20°

d. 145*2 is 290 than the total angle is 360 then minus 290 then divide by two