Answer:

PROBLEM:

Refer to the figure at the right.

What is the value of x?

SOLUTION:

• The sum of the interior angles of a triangle is 180°. Thus, if the two of the angle measures 50° and 60°, respectively, the other will be 70°.

\large50 \degree + 60 \degree + y= 180 \degree50°+60°+y=180°

\large110 \degree + y = 180 \degree110°+y=180°

\large y= 180 \degree - 110 \degreey=180°−110°

\large y = 70 \degreey=70°

• If the side of the triangle is extended outside the polygon, then another angle will be formed. That angle supplements the interior angle on the same vertex. Thus, they add upto 180°.

\large70\degree + x = 180 \degree70°+x=180°

\large x = 180 \degree - 70 \degreex=180°−70°

\large x = 110 \degreex=110°

• The given angles forms a linear pair.

ANSWER:

The value of x is 110°. Thus, the answer is Letter C.