We know that the total or the sum of all the angles in a triangle equal up to 180
For triangle ADC two angles are given 90 and 32 add these two and subtract the value from 180
180-90+32=x
180-122=x
58=x
angle C will be 58 in triangle ADC
we are suppose to find the angle C in triangle DCB so subtract 58 from 90
90-58=y
32=y
therefore angle DCB is 32
check the image below for understanding
hope this helped :)