A ladder placed against a wall will form a triangle with the wall and the ground. Using geometric ratios you can calculate the missing values. If you have an angle of 75.5 degrees and a hypotenuse/diagonal of 10, you need to calculate the height. Use sine.
Sine=opposite/hypotenuse
Sin75.5=0.97
0.97=opposite/10
10 x 0.97 = 9.7
The maximum height that the ladder can reach is 9.7 meters