Let
x------------> The length of one leg
y------------> The length of second leg
we know that
H=50 cm
x=2y
applying the Pythagorean theorem
H²=x²+y²--------> 50²=(2y)²+y²---------> 2500=4y²+y²-----> y²=2500/5
y=√500--------> y=22.4 cm
so
x=2y--------> x=2*22.4--------> x=44.8 cm
the answer is
the lengths of the legs of the triangle are
44.8 cm
and
22.4 cm