How Do You Find a Missing Angle in a Triangle?

How Do You Find a Missing Angle in a Triangle?

Note:

Trying to find a missing interior angle measurement in a triangle? Already know the other two interior angle measurements? Then you're set! Just remember that the interior angles of a triangle ALWAYS add up to 180 degrees. This tutorial shows you how to put this knowledge into an equation and solve to find that missing measurement!

Keywords:

  • triangle
  • triangles
  • triangle sum theorem
  • missing angle
  • angles
  • angle
  • add angles
  • sum of angles
  • find missing angle

Background Tutorials

  • Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

      • What is an Angle?What is an Angle?

      What is an Angle?

      Angles are a fundamental building block for creating all sorts of shapes! In this tutorial, learn about how an angle is formed, how to name an angle, and how an angle is measured. Take a look!

  • Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.

      • How Do You Add Decimals?How Do You Add Decimals?

      How Do You Add Decimals?

      Doing math with paper and pencil can come in real handy, so make sure you're comfortable adding decimals by hand. After all, you don't want the calculator to be a crutch!

  • Evaluate expressions at specific values of their variables. Include expressions that arise from formulas used in real-world problems. Perform arithmetic operations, including those involving whole-number exponents, in the conventional order when there are no parentheses to specify a particular order (Order of Operations).

Further Exploration

  • Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.

      • How Do You Find Missing Angles in an Isosceles Triangle?How Do You Find Missing Angles in an Isosceles Triangle?

      How Do You Find Missing Angles in an Isosceles Triangle?

      Trying to find a missing interior angle measurement in a triangle? See if you're working with a special type of triangle such as an equilateral or isosceles triangle. If you are, that knowledge can help you. In this tutorial, see how identifying your triangle first can be very helpful in solving for that missing measurement. Take a look!

      • How Do You Find Missing Angles in a Triangle With Variables?How Do You Find Missing Angles in a Triangle With Variables?

      How Do You Find Missing Angles in a Triangle With Variables?

      Looking for the measurements of the interior angles of a given triangle? The Triangle Sum theorem might help. This theorem states that the interior angles of a triangle ALWAYS add up to 180 degrees! This tutorial shows you how to use that information to find those interior angle measurements.