What is this angle ? A. It is an adjacent angle.
B. It is a right angle.
C. It is a vertical angle.
D. It is a supplementary angle.

Angles 1 and 3 are adjacent to angle 140. (because they are next to each other)

Angles 1 and 2, 1 and 140, 140 and 3, and 3 and 2 are supplementary (because together they add up to 180 degrees)

Angles 140 and 2 and 1 and 3 are vertical angles because they are across from each other.

This may be a little confusing, so don't be afraid to ask for clarification, but great luck!

no one knows lol

step-by-step explanation:

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.