Use the given formula
tan
θ
=
Length of wedge
Shadow length
tanθ=
Shadow length
Length of wedge
to find the shadow length
2 Rearrange the formula to find the shadow length:
Shadow length
=
Length of wedge
tan
θ
Shadow length=
tanθ
Length of wedge
3 Substitute the values:
Shadow length
=
77
mm
tan
θ
Shadow length=
tanθ
77 mm
4 Since the shadow length is not given, we can't find the altitude without additional information