What are the angle measures?

In geometry, an angle measure can be defined as the measure of the angle formed by the two rays or arms at a common vertex. Angles are measured in degrees ( °), using a protractor. Fun Facts. The protractor was invented by Joseph Huddart in 1801. It was a more complex form of protractor.

Step-by-step explanation:

a.  Equation:

3x + 21 = 6x - 60           {measure of corresponding angles is the same}

3x - 6x = -60 - 21

- 3x = - 81

b. Value of x:

  x = 27

c.  Ange measures:

3x + 21 = 3×27 + 21 = 81 + 21 = 102°

or:

6x - 60 = 6×27 - 60 = 162 - 60 = 102°

A)

× 3

----------

-7 × 3= -21

18 × 3= 54

A IS WRONG!