15x15= 225
15x + 105= 225
15x= 225-105
15x= 120
X=8
X+ (x+1) + (x+2) + (x+3)…etc all the way up too +(x+14)=225
The first five numbers of the set: 8, 9, 10, 11, 12
Use this version of the Law of Cosines to find side b:
b^2 = a^2 + c^2 − 2ac cos(B)
We want side b.
b^2 = (41)^2 + (20)^2 - 2(41)(20)cos(36°)
After finding b, you can use the Law of Sines to find angles A and C or use other forms of the Law of Cosines to find angles A and C.
Try it....
