The slope is:(9-3)/(1-(-2))=6/3=2
First two are scalene last one is isosceles.
So firstly, square root 9a^2 and 49: 
Next, combine like terms, and your answer will be
, or the third option.
This is a same side interior angle, which means that the two angles, when added, will equal 180°
y + 72 = 180
Isolate the y, subtract 72 from both sides
y + 72 (-72) = 180 (-72)
y = 180 - 72
y = 108
A) 108°, is your answer
hope this helps