Question

3. (02.07 MC)In the figure shown, what is the measure of angle x? (5 points)100 degrees110 degrees120 degrees140 degrees

Answer 1

The Solution:

Given:

We are asked to find the value of x.

By the sum of angles in a triangle, we have:

$\begin{gathered} \angle A+\angle B+\angle C=180 \\ In\text{ this case} \\ \angle A=40 \\ \angle B=70 \\ \angle C=? \end{gathered}$

So,

$\begin{gathered} 40+70+\angle C=180 \\ 110+\angle C=180 \\ \angle C=180-110=70^o \end{gathered}$

So, applying the theorem of angles in a straight line, we get

$\begin{gathered} x+70=180 \\ x=180-70 \\ x=110^o \end{gathered}$

Therefore, the correct answer is [option 2]