Answer:
793 liters of washing fluid is needed
Step-by-step explanation:
step 1
Find the slant height of the triangular faces of pyramid
we know that
The lateral area of a square pyramid is equal to the area of its four triangular faces
so
where
b is the base of triangle (is the same that the length of the square base)
l is the slant height
To find out the slant height we need to apply the Pythagorean Theorem
so
we have
substitute
step 2
Find the lateral area of the pyramid
we have
substitute
step 3
Find out how much window washing fluid is needed
we know that
2 L of washing fluid cover 5 square meters
so
using proportion
Round up
793 liters of washing fluid is needed