The image forms a right triangle. The missing side is the radius of the ice cup.
Apply the Pythagorean theorem:
C^2 = a^2 + b^2
Where:
c= hypotenuse (the longest side ) = 4.5
a & b = the other 2 legs of the triangle (4 and x )
Replacing:
4.5^2 = 4^2 + x^2
Solve for x (the missing side)
20.25 = 16 + x^2
20.25-16 = x^2
4.25 = x^2
√4.25 = x
2.06 = x
x =2.1 in
