Category Archives: Maths

Some Basic Trigonometry

It seems that doing maths for as long as I can remember didn’t make it stick in my mind so I’m having a little refresh as I go. I’m starting with some basic trig.

– Pythagorus’ Theorum – Find the length of a third side on a Right angled Triangle.

Very simple. Say we have a right angled triangle with sides a, b and c – where c is the hypotenuse…

Crucially, a² + b² = c²

AKA the sum of the areas of the two squares on the legs (a and b) equals the area of the square on the hypotenuse (c).

So how about this triangle?

5² + 9² = c²
25 + 81 = c²
c² = 106

Now square root 106…

c = ~10.30 (4sf) or √106 in surd form.