Answer:
∠B = 142 .15'
Step-by-step explanation:
Given : If ∠A and ∠B are supplementary and m∠A = 37°45',
To find : m∠B = ______.
Solution : We have given that ∠A and ∠B are supplementary.
We know that sum of two supplementary angle is 180 degree.
Then ∠A + ∠B = 180°
We have given m∠A = 37°45',
Plugging the value of angle A
37°45'+ ∠B = 180°
On subtracting by 37°45' both sides
∠B = 180° - 37°45'
Now convert the 45' in to degree
45' = 0.75 degree
Then 37° + 0.75° = 37.75°
∠B = 180° - 37.75°
∠B = 142 .25 °
We need our answer in degree and mint
1° = 60'
0.25° =15'
∠B = 142 .15'
Therefore, ∠B = 142 .15'