Answer:
Step-by-step explanation:
we know that
The measure of the interior angle in an equilateral triangle is equal to 60 degrees
The measure of the interior angle in a regular octagon is equal to
where
n is the number of sides
In this problem we have
substitute
we have that, based in the diagram
The sum of the interior angle of the equilateral triangle plus the interior angle of a regular octagon plus the value of x must be equal to 360 degrees (complete circle)
so
solve for x