math HELP plz
posted by Danielle D .
Richard is standing between two buildings in a townhouse development. The building on the left is 9m away and the angle of elevation to its security spotlight, A, is 68 degree. The building on the right is 6m away and the angle of elevation to its security spotlight, B, is 73degree. Which spotlight is farther away from Richard, and by how much?

Really don't understand need help.please

let the distances be a and b.
a/9 = sec 68°
b/6 = sec 73°
so,
a = 24.0
b = 20.5
so, a is farther away by 3.5m