Answer:

Step-by-step explanation:
Hello there!
The first thing we want to do is find the measure of the large leg
To do so we use the Pythagorean theorem which says 
where a and b are legs and c is the hypotenuse
we want to find b given the hypotenuse and short leg
so 
all we have to do is plug in a ( a = short leg so a would equal 12) and c ( c = hypotenuse so c would equal 37)
so

so the longer leg is equal to 35
35=5x
divide each side by 5
5x/5=x
35/5=7
we're left with x=7
Answer:
x=9 and the missing angle is 44
The correct answer is Choice B: 720.
To solve this, you have to use the Fundamental Counting Principal. You find the total number of options for each of the digits, then multiply them together.
For the first one, there are 10 options, then 9 options and finally 8 options.
10 x 9 x 8 = 720