The area of a circle formula tells us that . Let’s rearrange that to make the subject. Right now, is the subject.

We used our familiar operations: add, subtract, multiply, divide, raise to an exponent, take a root, open brackets, factor etc, to maintain equality while putting the value on its own on the left hand side.

Your turn!

The circumference of a circle is given by the formula . Rearrange to make the subject.

A straight line has equation . Rearrange to make the subject.

A straight line has equation . Rearrange to make the subject.

Pythagoras theorem tells us that for a right angled triangle, . Now is the subject of that formula. Rearrange to make the subject.

The area of a trapezium is given by the formula , where and are the parallel sides. Rearrange to make the subject.

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