The square root of 78 is approximately 8.83.
To find the square root of a number, you can use a calculator or estimate it by identifying two perfect squares between which the number lies. In this case, 64 (which is 82) and 81 (which is 92) are the nearest perfect squares.
Since 78 is between 64 and 81, we know that the square root of 78 will be between 8 and 9. To get a more accurate figure, you can use a calculator which will give you the square root as approximately 8.83176, which we can round to 8.83 for simplicity.