Tan(80 deg) is 5.67, maybe you are confused with Excel where the Tan function needs a number in Radians, so first you convert the degrees to radians and then use tan, like: =tan(radians(80))
Tan(80 deg) is 5.67, maybe you are confused with Excel where the Tan function needs a number in Radians, so first you convert the degrees to radians and then use tan, like: =tan(radians(80))