GED® Geometry: Right Triangles › 8. Word Problems: Draw the Hidden Triangle
Free trial session

8. Word Problems: Draw the Hidden Triangle

GED® Geometry: Right Triangles · preview lesson

Sign in to save

Many right-triangle questions hide the triangle inside a real situation. Your job is to draw it.

Distance = Pythagoras on the Grid A(1,1) B(5,4) 4 3 5 d = √(4² + 3²) = √25 = 5
A straight-line distance can be the hypotenuse of a hidden right triangle.

Common right-triangle setups:

  • A ladder against a wall: ladder = hypotenuse.
  • A ramp: ramp surface = hypotenuse; rise and run = legs.
  • A rectangle diagonal: diagonal = hypotenuse; length and width = legs.
  • A map or grid distance: east/west and north/south moves are legs; straight-line distance is the hypotenuse.

Routine:

  • Sketch the right angle.
  • Label the legs and hypotenuse.
  • Decide whether you are finding the hypotenuse (add) or a leg (subtract).
  • Check units and reasonableness. The hypotenuse should be the longest side.

Worked example: a person walks 12 blocks east and 5 blocks north. Straight-line distance:
\[ \sqrt{12^2 + 5^2} = \sqrt{144+25} = \sqrt{169} = 13. \]

Common mistake: adding the walking distances \(12+5=17\). That is the path walked, not the straight-line distance.

Quick Check

A rectangle is 7 by 24. What is the diagonal?

Lesson Discussion

Ask a question about this lesson. A teacher or admin can answer here.

0

No questions yet for this lesson.