Help pls

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

We just started the introduction into circles and i have no idea how to do this.

At the "no mutants allowed" country farm, every sheep has 4 legs, every chicken has two legs, and all animals have only 1 head. asked to count how many sheep and chicken are in the fields, a farm boy reports back that there are 140 feet and 50 heads. how many sheep and chicken are there? there are sheep and chicken at the farm.