The answer to what the length of the leg would be is 15.
You would do this problem by first writing down your Pythagorean Theorem, which is a^2 + b^2 = c^2.
Since we have our hypotenuse which is c^2 in our equation, we would write or insert the number we have.
So our equation could be that a or b leg equals 20, it doesn’t matter which one.
So we could write, 20^2 + b^2 = 25^2. So we don’t know what b leg is.
First we should figure out what 20^2 is and what 25^2 is.
20^2 is 400 and 25^2 is 625.
Our equation now comes to 400 + b^2 = 625.
Now we take 400 and subtract it from
625 -> 400 + b^2 = 625
-400.
So 625 - 400 comes out to be 225.
Lastly instead of squaring or putting 225 to the second power, we do the opposite.
So instead of squaring 225 we must square root 225. √ 225 .
The square root of √ 225 comes out to be 15.
You just need to plug those expressions inside the formula: it doesn't matter if they're expressions involving a variable instead of plain numbers: the formula becomes

If you want, you can simplify it by expanding the square and then multiply the two parenthesis:

Answer:
1.SAS, ASA,
2. Not congruent
3.C
4. If you could screenshot the whole page I can give tell you what it is.