Where where is the formula you didn't even post a picture?
The formula of a midpoint of a segment AB:

We have:
H(10; 1); K(4; 7)
substitute:

Answer: (7, 4)
Answer:
Since the interior angles of a triangle add up to be 180 degrees, I set up the equation like so:
x + 59 + x + 51 + 84 = 180 My equation
2x + 194 = 180 add like terms
2x = -19 subtract 194 from both sides of the equation
x = -7 divided both by 2x to get x alone
It has occurred to me that I am finding x here (it still makes no sense to get a negative number) but this is the only equation I know to set up.
Notes:
This is for geometry homework and I realize just asking you to solve my problems is academically dishonest off topic if I have not put genuine effort into the question, which I have (put effort in, that is). I have put a lot of mental effort into figuring this out, though, so I will tell you what I did and hopefully you can tell me where I went wrong and how to correct my mistake, because I think it is obvious I made one. For the record I accidentally deleted my math notes from my iPad and Googling the question this morning produces hard to understand results. My geometry teacher was unavailable while I was working last night due to my lack of internet connection.
Answer:
A vertical line has an infinite or undefined slope since the denominator is zero.
Step-by-step explanation:
Parallel lines by definition refers to lines that never intersect or meet since they have identical slopes. The slope of line is defined as;
(change in y)/(change in x)
For a vertical line, the y values are changing while the x values remain constant. The slope of this line will thus have a zero value in the denominator implying that its slope will not defined or will be infinity.