Question

Solve the triangle.

A = 51°, b = 11, c = 7 \

Answer 1

Ever heard the Pythagorean Theorem? ^.^

Answer 2

a2+b2=c2?

Answer 3

well in this case, more like \[\large a^2=b^2+c^2...\]

Answer 4

but this is no right triangle, so it doesn't really work out... :P

Answer 5

that's where the LAW OF COSINES comes into play :D

It's like the Pythagorean Theorem, but BETTER. It works for ANY triangle...


^.^ as long as you're either given all three sides or two sides and the angle between them, like here :P

Answer 6

With just a reeaallly tiny addition to the formula, we get the law of Cosines ^.^\[\Large a^2 = b^2+c^2 \color{red}{-2bc \ \cos(A)}\]

Answer 7

Now you can just solve for a :D

Answer 8

12.8?

Answer 9

@PeterPan