In triangle ABC A = 50 °, B = 30 °, calculate the degree measure C.

Given: ∆ABS, <A = 50 °, <B = 30 °.
Calculate: <C.
Solution.
The sum of three angles in a triangle is always 180 °. Let the angle C be equal to x, then we get the following expression: 180 ° = 50 ° + 30 ° + x; (further we solve it as a usual equation with the variable “x” (x)) x = 180 ° -50 ° -30 °; (we swapped the right and left parts and moved 50 ° and 30 ° to the right, changing their signs according to the transfer rule) x = 180 ° -80 °; x = 100 °. Since the angle is C = x, the angle is C = 100 °.
Answer: 100 °.