Consider the figure,
So, we have, Two angles are called complementary when their measures add to 90 degrees. Two angles are called supplementary when their measures add up to 180 degrees.
So, here, [tex]<\text{AHB}+z=180[/tex]
Therefore, z can be calculated as,
[tex]z=180-<\text{AHB}=180-105=75[/tex]
Now, the angles DHC and
