Your result is a fairly close approximation of the straight line distance from home plate to second base and is likely far more accurate than measuring the distance from home plate to first base or first base to second base. However, the size of the baseball may cause you to underestimate or overestimate the distance. If you were to use a ruler to measure the distance from home plate to first base, then your result would be very accurate but it would not be practical for field use. The reason is that there are many small stones in front of home plate which would break off under the weight of even one piece of equipment. This would be inconvenient for you as well as other players waiting their turn at the plate. You would also need to keep the stone pile clear of weeds so that it does not become an obstacle when you are trying to see balls hit into it. You are more likely to come across second base on a playground than home plate. This is because most playgrounds have some type of barrier between home and first bases to prevent children from running into the paths of moving vehicles or being hit by any falling objects such as rocks or ball bats. There is usually a large rock or brick monument near the batter's box to indicate where second base is located. This is so coaches can call time out if they need to discuss strategy with their players.