Na triangle, the second angle is twice the measure of the first, and the third angle is three times the measure of the second. find the measure of the third angle. a. 20 b.30 c.120 d.180

Interior angles of a triangle will add up to 180 degrees
x = 1st angle, y = 2nd angle and z = 3rd angle

y = 2x
z = 3yz = 3(2x)z = 6x
x + y + z = 180

x + (2x) + (6x) = 180
9x = 180
x = 180/9
x = 20 this is the 1st angle

y = 2x
y = 2(20)
y = 40this is the 2nd angle

z = 3y
z = 3(40)
z = 120 < and this is ur 3rd angle

C is your answer and below is how so. 
20x2=40
40x3=120
120+20+40=180
A triangle can't pass 180 degrees
a equilateral triangle is 60 60 60 
60x3=180