Answer: 7.81 feet
Explanation:
This scenario forms a right-angled triangle where Ruby's height of 5 feet is the height of the triangle. Her 6 feet long shadow is the length of the triangle and the distance from the top of her head to the end of the shadow is the hypotenuse.
This can therefore be solved by the Pythagorean formula:
c² = a² + b²
where ;
c = hypotenuse
a = height
b = length
c² = 5² + 6²
c² = 25 + 36
c² = 61
c = √61
c = 7.81 feet