Question

give him the equals 12 C equals 15 and M angle a equals 60° in triangle ABC use the law of cosines to solve for a fill in the blanks to complete each step if so pliable

Answer 1

You have a triangle ABC with the following parameters:

a = ?

b = 12

c = 15

m∠A = 60

In order to calculate the value of side a, you use the Law of Cosines, which is given by the following formula:

`a^2=b^2+c^2-2bc\cos (m\angle A)`

Then, by replacing into the previous equation you have:

`\begin{gathered} a^2=(12)^2+(15)^2-2(12)(15)\cos (60) \\ a^2=144+225-360(0.5) \\ a^2=189 \\ a=√(189)=13.74 \end{gathered}`

Hence, the value of the length of side a is 13.74