We can assume that the point the ladder creates with the ground and building is a triangle. You can use the Pythagorean theorem to solve this.
A^2 + B^2 = C^2
The ladder is C, and the building can act as A or B, so for the purpose of this explanation, I’ll make it A.
11^2 + B^2 = 14^2
Figure out the squares
121 + B^2 = 196
Subtract 121 from both sides
B^2 = 75
Square root B^2 and 75
B = 5 root3
