Answer:
47 degrees
Step-by-step explanation:
First let's find the measure of Angle CAB. We know that angles in a triangle add up to 180 so...
CAB+ACB+ABC=180
CAB+80+57=180
CAB+137=180
CAB=43
We also know that DAB is equivalent to 90 degrees as DAE and DAB are a linear pair which means they add up to 180 degrees. Since DAE is a right angle, DAB also has to be a right angle.
We can use DAB and CAB to find DAC:
DAC+CAB=DAB
DAC+43=90
DAC=47 degrees
