BA=16 ft because if one angle is 90 and another one is 45, the triangle is equilateral, so the third angle is 45.
Pythagorean theorem: BC²=AB²+AC²
BC²=256+256
BC²=512
BC=√512=16√2 ft.
Why 16√2? To put "16" under √ you need 16*16=256. Then you need 16*2=√512. So √512=16√2.
