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

Examples

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

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.

sqrt5=sqrt(L^2)

sqrt5=L

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