Question

Find the value of x. * 66 (3x + 21) 57°A)12B)15C)57D)10

Answer 1

We have a triangle with angles: 66 deg, 57 deg and (3x+21).

We have to solve for x.

We know that the sum of the interior angles of a triangles is 180 degrees.

Then, we can write and solve for x as:

$\begin{gathered} 66+57+(3x+21)=180 \\ 3x+21=180-57-66 \\ 3x+21=57 \\ 3x=57-21 \\ 3x=36 \\ x=\frac{36}{3} \\ x=12 \end{gathered}$

The value of x is 12.

Answer: A) 12