Question 149772
You haven't said so in your problem description but the only way to get an answer is to assume that it is a right triangle with the hypotenuse, c = 19 and the other two legs are x and 3x each.
So, proceeding on this assumption, you can use the Pythagorean theorem to find the value of x and, thus, the lengths of sides a and b.
{{{c^2 = a^2+b^2}}} Substitute c = 19, a = x, and b = 3x.
{{{19^2 = x^2+(3x)^2}}} Simplify and solve for x.
{{{361 = x^2+9x^2}}}
{{{361 = 10x^2}}} Divide both sides by 10.
{{{36.1 = x^2}}} Take the square root of both sides.
{{{6.008 = x}}}

Side a = 6.
side b = 3(6) = 18.