Find the missing value of a right triangle
a=
b=12
c=15

In a right triangle, angle must obeys Pythagoras theorem:
c² = a² + b²
15² = a² + 12²
225 = a² + 144
a² = 225 - 144
a² = 81
a = √81
a = 9

In short, Your Answer would be 9

Hope this helps!

You would need to use the Pythagorean theorem to solve this. 
There is one equation that you use to find the hypotenuse or c 
c=√a²+b²
Since we already have c we need to use the equation to find a leg 
a=√c²-b²
Now we just plug in all the information we know
a=√15²-12²
a=√225-144
a=√81
a=9

Where the white dots are is where your points should be plotted.a translation is simply just moving something from one place to another. in this case, you would move each plot point of the original shape 2 units up, and 5 units to the left.