Answer
3 ft
Work Step by Step
Use the figure given in the Exercise.
Step 1. Identify the given quantities: radius of the sphere $R=5$ ft, metal circle is $h=4$ ft below the center of the sphere, the metal circle has a radius of $r$.
Step 2. Draw a diameter across the metal circle and form a triangle with the center of the sphere, the height of the triangle is $h=4$ and the length of equal sides is $R=5$
Step 3. Use the Pythagorean Theorem, the radius of the metal circle satisfies $r^2=R^2-h^2=25-16=9$, thus the radius of the metal circle is $r=3$ ft.
