To find the measurement of the other side of a right triangle when given the hypotenuse and one of the sides, you can use the Pythagorean theorem. The theorem states that in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.

Let's denote the unknown side as 'x.'

According to the Pythagorean theorem, we have:

x^2 + 25^2 = 46^2

x^2 + 625 = 2116

x^2 = 2116 - 625

x^2 = 1491

Taking the square root of both sides, we get:

x = 1491

So, the measurement of the other side (the horizontal side) is approximately 38.63.