Finding Missing Angles in Quadrilaterals

What is the first step in calculating the missing angle in a quadrilateral?

How many degrees do the angles in a triangle add up to?

What is the sum of the angles in a quadrilateral?

If a quadrilateral has angles of 105, 75, and 80 degrees, what is the missing angle?

In the first example, what is the sum of the given angles before finding the missing angle?

What is the missing angle in a quadrilateral with angles 56, 64, and 110 degrees?

In the second example, what is the sum of the first two angles added together?

What is the algebraic expression used to find the missing angle in the second example?

How do you verify the solution in the second example?

What is the correct calculation to find the missing angle in the second example?