Engineering: Radicals are indeed used in engineering to compute various quantities such as stresses, forces, and other physical properties that have to deal with roots, especially in the utilization of formulas derived from the principles of mechanics and dynamics.
Physics: In many areas of physics, radicals come up due to the nature of oscillatory motion, for example, the period of a pendulum is proportional to the square root of the length divided by gravity. In addition, radicals typically occur in wave functions of quantum mechanics, particularly in the solution of Schrödinger's equation.
Architecture: The architect's use of radicals is in the determination of diagonal distances within which structures are to be designed so that they are proportionally valid and pleasant-looking. The determination of the hypotenuse of right triangles is common in many design cases that have square roots in them.
Survey: This is why surveyors use radicals when they measure land, most especially in topographical mapping where elevation changes make for irregular terrains. Determining the actual ground distance over the uneven surfaces often uses the Pythagorean theorem in the application process, which involves square roots.