So if you knew that all angles in triangles add up to 180 degrees. You first want to find Y. 180 - 36 - 70 is equal to 74. So, Angle Y is 74 degrees. Line XYZ is a line that has a 180 degree on there. So 180 - 74 and divide that by 2 to find X and Z. 180 - 74 is 106. 106/2 = 53. Therefore, X and Z are 53 degrees, Y is 74 degrees.
The size of the lawn is not dependent how much water is used, however the amount of water used is dependent on the size of the lawn (be it larger or smaller).