Part 23 - Worded questions using surds III | Maths Made Easy

# Surds GCSE Maths Revision

## Part 23 – Worded questions using surds III

Example:

A pyramid in the Egyptian plateau has a base length of √5 m , base width of 3√3 m and a height of √2 m.Given that Volume (V)=1/3×base length (l)×base width (w)×height (h) i.e. =1/3 lwh , calculate the volume of the pyramid.

Worked Solution:

The formula for the Volume of a pyramid is V=1/3 lwh , if l=√5 m w=3√3 m and h=√2 m then:

V= 1/3 lwh=1/3×√5×3√3×√2=(√5×3√3×√2)/3

Divide top and bottom by 3:

V= (√5×3√3×√2)/3=√5×√3×√2=√(5×3×2) (hint: use the formulae from previous slides)

=√(5×3×2 )=√30

Hence, V=√30 m (note: don’t forget to write the units; it is m3 because we are dealing with a volume of a shape).