This will involve finding an arctangent.
We'll consider the woman's height as the "opposite" side of a triangle and the shadow as the "adjacent" side. The angle that the Sun makes equals the arc tangent of that angle.
tan (Sun's angle) = 71" / 36"
tan (Sun's angle) =
1.9722222222
when we determine the arc tangent of 1.9722222222, it will equal the Sun's angle.
arc tangent of 1.9722222222 = 63.113 degrees
