Final: Triangle Meets Line

Part of the Angles section of Coddy's Geometry journey. Lesson 59 of 62.

A triangle with an extended side: the exterior angle theorem’s home ground. Watch the minus sign inside the label: (x - 10)° means 10 less than x, and the minus rides along like any number.

Challenge

Medium

The exterior angle measures 98°; the remote interior angles are (x - 10)° and 48°.

$A triangle with exterior angle 98 degrees and remote interior angles x minus 10 and 48 degrees$

Find x.

Try it yourself

(x - 10) + 48 = 98

Solve for x

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Angles

2Straight Lines and Supplements

Angles on a Line Supplementary Angles Three Angles on a Line Write the Equation Recap: Along the Line

5Around a Point

Angles Around a Point The Missing Angle Equal Slices Four Angles, One Point Recap: The Full Turn

8Transversal Problems

Both Angles Labeled Verticals Meet Parallels From Figure to Equation Alternate with Algebra Recap: Through the Strip

11The Exterior Angle

The Exterior Angle Using the Shortcut Two Roads, One Answer Exterior in the Wild Recap: Outside View

3Right Angles and Complements

Complementary Angles Finding the Complement Perpendicular Lines Equal Parts of a Corner Recap: The Right Corner

6The Angle Bisector

The Angle Bisector Bisected Expressions Bisecting a Straight Angle Recap: Split in Half

9Triangle Angle Sum

The 180 Rule Finding the Third Angle Two Unknown Angles Right Triangles Recap: The Budget

12Final Challenges

Final: The Angle ChaseFinal: Triangle Meets LineFinal: The Full Round Final: Isosceles Chase Final: Master of Angles