[Jim S]

No Dylan it isn't.
A baseball, or softball diamond, is a square of the dimension (60, 70, 90ft etc.) you happen to be using. First and third base are placed on the inside corners of that square. (Second base is centered on the insection of the lines from the back of 1st & 3rd base. Therfore 1/2 of second base is within the infield and 1/2 is in the outfield.[the infield is technically only the part of the fied within the measured square, therefore many "infield" hits really aren't])
Most bases are a 15 inch square. Home plate extends up the baseline aproximately 12 inches. Therefore the distance between home plate and 1st base on a 70 foot diamond is about 67 feet 9 inches.