U
Uncorrupted.Innocence
Guest
Problem: Find Angle A if; side a = 18, side b =24, and angle C =90
**NOTE: This is a regular triangle, not a right triangle
I've already found side C using Law of Cosines:
Side c = 30.
AM I DOING THIS PART CORRECTLY?
Then I started to find angle A with the law of Cosines, but I got stuck.
**NOTE: "a(sub)2" means side a squared.
a(sub)2 = b(sub)2 + c(sub)2 - 2(b)(c)(Cos A)
18(sub)2 = 24(sub)2 + 30(sub)2 - 2(24)(30)(Cos A)
324 = 576 + 900 -1440(Cos A)
324 = 1476 - 1440(Cos A)
324 = 36(Cos A)
324/36 =36(Cos A)/36
9 = Cos A ---- Now at this part, what does this mean? What do I do from here?
**NOTE: This is a regular triangle, not a right triangle
I've already found side C using Law of Cosines:
Side c = 30.
AM I DOING THIS PART CORRECTLY?
Then I started to find angle A with the law of Cosines, but I got stuck.
**NOTE: "a(sub)2" means side a squared.
a(sub)2 = b(sub)2 + c(sub)2 - 2(b)(c)(Cos A)
18(sub)2 = 24(sub)2 + 30(sub)2 - 2(24)(30)(Cos A)
324 = 576 + 900 -1440(Cos A)
324 = 1476 - 1440(Cos A)
324 = 36(Cos A)
324/36 =36(Cos A)/36
9 = Cos A ---- Now at this part, what does this mean? What do I do from here?