Brush up your maths: answer to squares and square roots exercise

Calculate the following: 3² + (–2)², √144, and √(3² + 4²).

3² + (–2)² = 9 + 4 = 13.

Three squared is 3 × 3 = 9, minus two squared is (–2) × (–2) = 4.

√144 = 12.

Twelve twelves are 144.

√(3² + 4²) = √(9 + 16) = √(25) = 5

First we evaluate the bracket, according to the BODMAS rule. Within the the bracket, we do "powers of" first, then we add. Square root is a power, as we shall see later in Powers. We do this next. (In this case, of course, there is nothing else to do anyway.)

(If you just said, "Easy, that's the 3-4-5 triangle of Pythagoras' theorem", good for you! You may not need me.)

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Last updated: 27 September, 2007.