What do the angles of any four-sided figure add up to?

What do the angles of any four-sided figure add up to?

• A. 180 degrees
• B. 360 degrees
• C. 720 degrees
• D. 90 degrees

Answer: (B)

The angles of any four-sided figure add up to 360 degrees. Think of a quadrilateral being split into two triangles by drawing a diagonal. Each triangle’s interior angles sum to 180 degrees, so together they total 180 + 180 = 360 degrees. You can also use the general rule for polygon interior angles: (number of sides minus two) times 180. For a four-sided figure, that’s (4 − 2) × 180 = 360. The other sums don’t fit: 180 is the total for a triangle, 720 corresponds to a six-sided figure, and 90 is just a single angle, not a total.

The angles of any four-sided figure add up to 360 degrees. Think of a quadrilateral being split into two triangles by drawing a diagonal. Each triangle’s interior angles sum to 180 degrees, so together they total 180 + 180 = 360 degrees. You can also use the general rule for polygon interior angles: (number of sides minus two) times 180. For a four-sided figure, that’s (4 − 2) × 180 = 360. The other sums don’t fit: 180 is the total for a triangle, 720 corresponds to a six-sided figure, and 90 is just a single angle, not a total.