Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 3 - No. 7)
What are the essential requirements for using the cosine rule to find an angle?
Two sides and the included angle
All three sides
Two angles and a side
Any two sides
ব্যাখ্যা
The cosine rule is used when knowing all 3 sides, or 2 sides and included angle.