Suppose a triangle has two sides of length 3 and 4 and that the angle between these two sides is 60°. what is the length of the third side of the triangle? a) 3 b) square root 13 c) 4 square root 3 d) square root 3

sqrt(13)

B

Step-by-step explanation:

This problem uses the Cos law

Givens

a = 3b = 4C = 60 degrees

Formula

c^2 = a^2 + b^2 - 2*a*b*Cos(C)

Solution

c^2 = a^2 + b^2 - 2*a*b*Cos(C)     Substitute givensc^2 = 3^2 + 4^2 - 2*3*4*Cos(60)   Evaluatecos(60) = 1/2                                   Evaluatec^2 = 9 + 16 - 2* 3 * 4 * 1/2             Add the first two term. The third term is 12 c^2 = 25 - 12                                   Subtractc^2 = 13                                           Take the square root of both sides.c = sqrt(13)                                       Answer