Geometry 4-7 Complete Lesson: Congruence in Overlapping Triangles

By Matt Richardson
Last updated about 3 years ago
26 Questions
Note from the author:
A complete formative lesson with embedded slideshow, mini lecture screencasts, checks for understanding, practice items, mixed review, and reflection. I create these assignments to supplement each lesson of Pearson's Common Core Edition Algebra 1, Algebra 2, and Geometry courses. See also mathquest.net and twitter.com/mathquestEDU.

Solve It! An assignment for your graphic design class is to make a colorful design using triangles. How many triangles are in your design? Enter only a number.

Take Note: Define common angle (in overlapping triangles). On the canvas, sketch a pair of overlapping triangles and label a common angle.

Take Note: Define common side (in overlapping triangles). On the canvas, sketch a pair of overlapping triangles and label a common side.

Problem 1 Got It?

Problem 1 Got It?

Problem 2 Got It? Complete the proof on the canvas.

You may also complete your work on paper or on a whiteboard and upload a clear picture of it to the canvas.

Problem 3 Got It? Complete the proof on the canvas.

You may also complete your work on paper or on a whiteboard and upload a clear picture of it to the canvas.

Problem 4 Got It? Complete the proof on the canvas.

You may also complete your work on paper or on a whiteboard and upload a clear picture of it to the canvas.

Separate and redraw the overlapping triangles. Label the vertices.

You may also complete your work on paper or on a whiteboard and upload a clear picture of it to the canvas.

Separate and redraw the overlapping triangles. Label the vertices.

You may also complete your work on paper or on a whiteboard and upload a clear picture of it to the canvas.

Reasoning: In Exercise 1, both triangles have vertices J and K. Are ∠J and ∠K common angles for △MKJ and △LJK? Explain. You may also use the canvas to help illustrate your explanation.

Reasoning: In the figure, which pair of triangles could you prove congruent first in order to prove that △ACD ≅ △CAB ? Explain. You may also use the canvas to help illustrate your explanation.

Enter only the word that fills the blank, with no spaces.

Enter only the word that fills the blank, with no spaces.

Enter only the word that fills the blank, with no spaces.

Review Lesson 3-6: Complete the construction using the GeoGebra geometry utility (embedded below or at geogebra.org/geometry). Screenshot your final product and upload it to the canvas. Be sure to label all points and leave any evidence that indicates how you completed the task.


Draw a line p and a point M not on p. Then construct line n through M so that n is perpendicular to P.

You may leave lines and points unlabeled.

Review Lesson 1-7: Find the coordinates of the midpoint of the segment with the given endpoints.

Review Lesson 1-7: Find the coordinates of the midpoint of the segment with the given endpoints.
Enter your response in this format, no spaces: (-3.5,14).

Review Lesson 1-7: Find the coordinates of the midpoint of the segment with the given endpoints.
Enter your response in this format, no spaces: (-3.5,14).

Vocabulary Review: Identify the common side of each pair of triangles.

  • \overline{RP}
  • \overline{AB}
  • \overline{ZY}
  • \overline{RT}
  • \overline{WX}
  • \overline{WY}
  • \overline{AC}
  • △ABC and △ADC
  • △XWZ and △YWZ
  • △RST and △RPT

Use Your Vocabulary: Refer to the diagram and identify the common regions of the overlapping figures named on the right.

  • △BEC
  • △EHD
  • △GHB
  • △ABG
  • △ACF
  • △GDF
  • △FGD and △CBE
  • △BEC and △HED
  • △ACF and △ABG

Reflection: Math Success