
Eugene J. answered 05/31/21
UIUC undergrad teaching Math and CS
The distance from home plate to second base is the same as the diagonal of the baseball diamond (a square). So basically, the question is asking us to find the diagonal of a square with side lengths of 90 feet.
The length of a square's diagonal is the side length times the square root of 2 (split a square into two 45-45-90 triangles and use the Pythagorean theorem to find the length of the hypotenuse, which has the same length as the diagonal of the square), so our answer comes out to be 90 * sqrt(2), which comes out to be around 127.3.