Find the measure of angle x in the figure below: a triangle is shown. at the top vertex of the triangle is a horizontal line aligned to the base of the triangle. the angle formed between the horizontal line and the left edge of the triangle is shown as 56 degrees, the angle formed between the horizontal line and the right edge of the triangle is shown as 51 degrees. the angle at the top vertex of the triangle is labeled as y, and the interior angle on the right is labeled as 72 degrees. the interior angle on the left is labeled as x. 35° 47° 73° 78°

I attached a diagram representing the given scenario.

y = 73°
x = 35°

Explanation:
1- getting the value of y:
We know that a straight angle has a measure of 180°.
We can note that:
The three angles 51° , 56° and y form a straight angle.
This means that:
51 + 56 + y = 180
107 + y = 180
y = 180 - 107
y = 73°

2- getting the value of x:
Now, in any triangle, the sum of the interior angles must be 180°.
In the given triangle we have:
an angle measuring 72°
an angle y measuring 73°
an angle x that we want to find
Therefore:
72 + 73 + x = 180
145 + x = 180
x = 180 - 145
x = 35°

Hope this helps :)