So do you need it as a percent or a fraction?
X-intercept is (-3,0)
Y-intercept is (0,6)
The equation is y=2x+6
Replace y with 0 when solving for x-intercept and replace x with 0 when solving for y-intercept.
I am a little confused about the question you are trying to ask. It is an isosceles triangle because it has two sides of equal length.
The other angle would be...
180-2(55)=70 degrees
There were no slopes listed below but in order for two equations to be parallel they need to have the same slope. So in this case any equation with a slope of 5x would be parallel to your equation.