Part 22 - Worded questions using surds II | Maths Made Easy

Surds GCSE Maths Revision

Part 22 – Worded questions using surds II

Example:

A toblerone has a base length of √3 cm and a height of 4+2√2 cm . Calculate the area of the triangular toblerone.

Worked Solution:

Formula for the Area of a triangle is Area (A)= 1/2×base (b)×height (h) i.e. A= 1/2 bh , if b=√3 cm and h=4+2√2 cm then:

A= 1/2 bh = 1/2×√3×(4+2√2) = √3/2(4+2√2)

Expand the bracket and simplify:

A= √3/2 (4+2√2)=(4×√3)/2+(2×√3×√2)/2=(4√3)/2+(2√3×2)/2

(hint: use the formulae from previous slides).

=(4√3)/2+(2√6)/2 = 2√3+√6

Hence, A= 2√3+√6 cm2 (note: don’t forget to write the units; it is cm2 because we are dealing with an area of a shape).


Your turn:

A toblerone has a base length of 2/3+8√7 cm and a height of 6√5 cm .

Calculate the area of the triangular toblerone.

Your answer can be written in the form: a√5+b√35 cm2

Find the value of a and b.

Enter your answer here:
a =
b =

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