You are shown a diagram of a right angled triangle, with the hypotenuse labelled c and the other sides labelled a and b. If a is 7m long and c is 10m long, what is the length of b?
A simple implementation of Pythagoras' Theorem a2+b2=h2, and as in the question c is the hypotenuse, a2+b2=c2. (Side Note - in exams, the question may not specify which length is the hypotenuse - this is always the longest length of the triangle!)
To get the length b, the formula must be rearranged so that we have something of the form 'b=...'. In order to do this, we must subtract 'a2' from the left hand side (LHS) of the equation, but to preserve the equality (the equals sign) a2 must be subtracted from the right hand side (RHS) too. This gives b2=c2-a2. Finally, both sides must be square rooted, so we have b=(c2-a2)1/2 (Side Note - something to the power of a half is the same as square rooting it!). Putting in the numbers, we are left with 7.141m. (Remember - UNITS!)
