triangle GHE

GH=10
HE = 17
hypotenuse GE =21
HF is an altitude

Find HF

2 answers

10, 17, 21 IS NOT a Right triangle, no hypotenuse here
In general

h = 2*area/base
here the base is EG = 21

the area is
sqrt[ s(s-a)(s-b)(s-c) ]
where s = (a+b+c)/2