Mammoth Memory

Exact answers

If your answer is a surd or `pi` then you can’t get a more accurate number (as long as they have been simplified).

Exact answer = Surd or `pi`


1.   The area of a square = 5m2, what is the exact length of one side of the square?

When measuring a square the answer doesn’t need simplifying

Area of a square = Length x Height

And in this case as length and height are the same

Area of a square = Length x Length

Area of a square = L2

Therefore   5m2 = L2

Whatever you do to one side of an equation, you must also do to the other.

So, the square root of both sides.



Answer:   Exact length =`sqrt5`


2.  Find the exact area of a circle with radius 5

Area of a circle = `pir^2`

Area of a circle = `pi5^2`                          

                           = `pi25` `m^2`

Answer:  Area of a circle = `pi25` `m^2`

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