SAT Practice Math Questions: Angle Problems - dummies

SAT Practice Math Questions: Angle Problems

By Geraldine Woods, Ron Woldoff

Angles are a big part of the SAT geometry problems. Finding an angle is usually a matter of simple addition or subtraction, provided you remember these key facts.

  • There are no negative angles.
  • There are no zero angles.
  • Fractional angles rarely appear on the test. For example, an angle is unlikely to measure


Here are some angle questions to get you started.

Practice questions

  1. In the following drawing,


    Find the measure, in degrees, of the angle marked x.


  2. What is the sum of the angles marked a, b, c, and d in the following diagram?


    A. 180 degrees
    B. 360 degrees
    C. 540 degrees
    D. 720 degrees

Answers and explanations

  1. 40 degrees. Because this drawing contains parallel lines cut by transversals (the two lines meeting at point A), you can fill in a whole lot of angles right off the bat. Each transversal creates eight angles, and these angles come in two groups of four pairs of vertical and supplementary angles. (Remember, a pair of vertical angles is two angles opposite each other and equal to each other. Supplementary angles total 180 degrees.) Here they are, filled in:


    After you determine the angles, the problem becomes simpler. Because ACD is a triangle, its angles must add up to 180 degrees. With a 60-degree and an 80-degree angle already accounted for, the missing angle must be 40 degrees — your correct answer.

    Don’t grid-in the degree symbol, just the number.

  2. B. This one you just have to memorize. The sum of the exterior angles of any shape is always 360 degrees. Remember that fact.