Question

in a triangle ABC, AB =sqrt2, AC = 1/sqrt2 and the angle at A is 60 deg, Find the length of BC and the size of the angle at C.

Answer 1

use cosine law.

Answer 2

any chance you could show how

Answer 3

http://www.youtube.com/watch?v=pGaDcOMdw48

Answer 4

BC uses the Cosine Rule or laws of Cosine... the Angle C is found using the Sine Rule or Laws of Sine

start by drawing a diagram



1st find BC using the Cosine Rule

remember a = BC c = AB and b = AC

\[a^2 = b^2 + c^2 - 2ab \cos(A)\]

substitute and evaluate.

2. Find angle C using the Sine Rule

\[\frac{\sin(C)}{c} = \frac{\sin(A)}{a}\]

again substitute and evaluate