Find the surface area of a square pyramid with side length 5 cm and slant height 4 cm.

h = height

s = slant height

a = side length

P = perimeter of base

e = lateral edge length

r = a/2

V = volume

L = lateral surface area

B = base surface area

A = total surface area

Explanation:

Volume of a square pyramid:

V = (1/3)a2h

Slant Height of a square pyramid:

By the pythagorean theorem we know that

s2 = r2 + h2

since r = a/2

s2 = (1/4)a2 + h2, and

s = √(h2 + (1/4)a2)

This is also the height of a triangle side

Lateral Surface Area of a square pyramid (4 isosceles triangles):

For the isosceles triangle Area = (1/2)Base x Height. Our base is side length a and for this calculation our height for the triangle is slant height s. With 4 sides we need to multiply by 4.

L = 4 x (1/2)as = 2as = 2a√(h2 + (1/4)a2)

Squaring the 2 to get it back inside the radical,

L = a√(a2 + 4h2)

Base Surface Area of a square pyramid (square):

B = a2

Total Surface Area of a square pyramid:

A = L + B = a2 + a√(a2 + 4h2))

A = a(a + √(a2 + 4h2))

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.