How do I know whether to add or minus in Pythagoras's theorem?
Firstly it has to be a right angled trinagle. Even if it is an irregukar shape, draw a line in to make it a right angled triangle. When you have your right angled triangle remember it is ALWAYS + if it is the hypotenuse (longest side) and - if it is not the hypotenuse.
NM
Related Maths GCSE answers
All answers ▸How do you find 24% of 1546?
a)By completing the square, prove the quadratic formula starting from ax^2+bx+c=0, b) hence, or otherwise solve 3x^2 + 7x -2= 9, to 3s.f.
A straight line runs through these two coordinates (1,5) and (4,7), find the equation of the line.
A line has equation y=3x+4, state the gradient and the y-intercept