Question

A written explanation solving the question how much fluid is needed using the Pythagorean method and finding the area of the triangle

Answer 1

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

$LA=4[\frac{1}{2}bl]$

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

$l^2=(b/2)^2+h^2$

we have

$b=35.42\ m$

$h=21.64\ m$

substitute

$l^2=(35.42/2)^2+21.64^2$

$l^2=781.9337$

$l=27.96\ m$

step 2

Find the lateral area of the pyramid

$LA=4[\frac{1}{2}bl]$

we have

$l=27.96\ m$

$b=35.42\ m$

substitute

$LA=4[\frac{1}{2}(35.42)(27.96)]$

$LA=1,980.6864\ m^2$

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

$\frac{2}{5}\ \frac{L}{m^2}=\frac{x}{1,980.6864}\ \frac{L}{m^2}\\\\x=1,980.6864(2)/5\\\\x= 792.27\ L$

Round up

793 liters of washing fluid is needed