If the hypotenuse of a triangle is x and the shortest leg is x/4 then what's the length of the remaining side?

We have, by the Pythagorean Theorem....

√ [x^2 - (x/4)^2] =

√ [(16x^2 - x^2) / 16]=

[√(15)/4 ] x

i answer the question with a question. what mindset do you have to be in to understand this? its like hyrogleiphics.