Small Python+Numpy function to compute screen sizes given aspect ratio and diagonal length.

screen_sizes.py

from numpy import array, sqrt


def xy_sizes(diagonal, aspect_ratio, units='centimeters'):
    r"""
    This function computes the horizontal and vertical lengths of a screen
    given its diagonal length and the aspect ratio. The system of equations to
    be solved admits a unique feasible solution in closed form. The system is
    given by these two equations:
        x / y = aspect_ratio
        x^2 + y^2 = diagonal^2
    Solve for x and y, keeping in mind that both have to be strictly positive,
    and you obtain the formulae below.
    """

    y = sqrt( diagonal**2 / (1 + aspect_ratio**2) )
    x = aspect_ratio * y

    sizes = array((x, y))
    if units == 'centimeters':
        sizes *= 2.54

    return sizes


sl315 = xy_sizes(15, 3/2)
t470 = xy_sizes(14, 16/9)
n550 = xy_sizes(15.6, 16/9)
xps15 = xy_sizes(15.6, 16/10)
xps17 = xy_sizes(17, 16/10)
mbp16 = xy_sizes(16, 16/10)


print( '| Device                 | Width (cm) | Height (cm) |')
print( '|------------------------|------------|-------------|')
print(f'| Surface Laptop 3, 15"  | {sl315[0]:10.2f} | {sl315[1]:11.2f} |')
print(f'| ThinkPad T470, 14"     | {t470[0]:10.2f} | {t470[1]:11.2f} |')
print(f'| ASUS VivoBook Pro, 15" | {n550[0]:10.2f} | {n550[1]:11.2f} |')
print(f'| Dell XPS 15            | {xps15[0]:10.2f} | {xps15[1]:11.2f} |')
print(f'| Dell XPS 17            | {xps17[0]:10.2f} | {xps17[1]:11.2f} |')
print(f'| MacBook Pro 16"        | {mbp16[0]:10.2f} | {mbp16[1]:11.2f} |')