Which one? . triangle abc has the angle measures shown below.

measure of angle A is 20

step by step explaination:

sum of all three angles of a triangle = 180°

therefore angle s( A+B+C)= 180°

substitute the values of a, b and c angles

2x+5x+11x = 180

18x = 180

x= 180/18= 10 °

now check each given answers by putting the value of x, you will find only measure of 2x = 2x10= 20

idn

step-by-step explanation: