Question

Suppose a triangle has three sides of length of 3 and 4 in that the angle between these two sides is 60°. What is the length of the third side of the triangle

Answer 1

3.61 in. to the nearest hundredth.

Explanation:

You use the Cosine Rule to solve this.

a^2 = b^2 + c^2 - 2bc cos 60 where a is the third side.

Plugging in the given values:_

a^2 = 3^2 + 4^2 - 2*3*4* cos 60

= 9 + 16 - 24*0.5

= 13

a = √13

= 3.61