Geometry: Finding a Side Length in Triangle Using Centroid

Click For Summary
SUMMARY

The discussion focuses on determining the length of side BC in a triangle using the properties of congruency and the centroid's location. The centroid divides the median into segments with a ratio of 2:1, allowing for the application of the Pythagorean Theorem once the necessary dimensions are established. The user successfully identified that AG equals 6 and the distance from the centroid to side BC is 3, leading to the conclusion that the centroid's position in a right triangle is at b/3 and h/3 from the right angle. This understanding facilitates the calculation of the missing side length.

PREREQUISITES
  • Understanding of triangle properties and congruency
  • Knowledge of centroids and their properties in triangles
  • Familiarity with the Pythagorean Theorem
  • Basic geometric construction skills
NEXT STEPS
  • Study the properties of centroids in various types of triangles
  • Learn how to apply the Pythagorean Theorem in triangle problems
  • Explore congruency criteria for triangles, such as SSS and SAS
  • Practice solving problems involving medians and centroids in geometry
USEFUL FOR

Students studying geometry, educators teaching triangle properties, and anyone looking to enhance their problem-solving skills in geometric contexts.

The Head
Messages
137
Reaction score
2
The Problem is #16 in the attached picture. Essentially, I need to find the length of BC using information about congruency and the location of the centroid. I've been able to show a whole bunch of things, but nothing that gets me close to actually finding out the missing side length.

I began by drawing all of the other medians through point G, which forms triangles AGE and CGE. Some of the things I logically inferred were (note, when I use "=" below I sometimes mean congruent-- I do know the difference):
BG=GD=2GE=2ED
AE=EC
triangle AED = triangle CEG
triangle AEG = triangle CED
AG=6 (because of congruent triangles) and the distance along the median from G to the side of BC is 3 (because distance from centroid to side length is 1/3 length of median)

These congruent triangles a lot of sides and angles to be congruent, but I can't really make any progress on specific values. Please help me make some real progress with this problem!
 

Attachments

  • IMG_2479.JPG
    IMG_2479.JPG
    60.6 KB · Views: 813
Physics news on Phys.org
I moved the thread to our homework section.
The Head said:
AG=6
That is a good start.

What do you know about the position of the centroid in a right triangle?
 
Ahh I can see now! It's b/3 and h/3 away from the right angle and then we can just use the Pythagorean Theorem. Thank you.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 30 ·
2
Replies
30
Views
5K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
18
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K