In any right-angled triangle where a, b and c are the length of the sides and c is the hypotenuse:
a2+b2=c2 In any right-angled triangle ABC where a, b and c are the length of the sides and c is the hypotenuse:
sinA=cacosA=cbtanA=ba In any triangle ABC where a, b and c are the length of the sides:
sine rule: sinAa=sinBb=sinCc cosine rule: a2=b2+c2−2bccosA Area of triangle=21absinC