Step-by-step explanation:
Let the angle near point A be
.
Let the angle near point B be
.
Let the angle near point C be
.
Let the external angle near point A be
.
Let the external angle near point B be
.
Let the external angle near point C be
.
According to exterior angle property,exterior angle of an angle is the sum of other two angles.
So,

According to angle sum property,the sum of angles in the triangle add to 

Step-by-step explanation:
1. B
2. B
There are no numbers for this, thus you will have to use the quadratic formula.
To find the x-intercept, you simply make y equal to 0 and solve the equation for x. To find the y-intercept, you make x equal to 0 and solve for y. So, for number 1, the answer is D because when you set it to y equals 0, you get x=3 and when you set it to x equals 0, you get 4.
Number 2 we would do the same thing and get D as well.
Hope this helps!