To solve this, I set angle one as x, since we don't know the value of it yet. Angle 2 is twice the first, I made it 2x, and made the third 3x by the same logic. We know that a triangles angles add up to 180 degrees. This means we can make the equation x+2x+3x=180. This simplifies to 6x=180 and so we get the answer that the first angle is 30 degrees.
Answer: The measure of third angle is 120°
Step-by-step explanation:
Let the measurement of first angle is x degree,
Then according to the question,
The measurement of second angle = 2x degree
While, the measurement of third angle = 6x degree,
Since, the sum of all three angles of a triangle = 180°
⇒ x + 2x + 6x = 180°
⇒ 9x = 180°
⇒ x = 20°
Hence, the measurement of third angle = 6x = 6×20° = 120°
⇒ Option C is correct.
