Free · Algebra and geometric relations
Recover Triangle Vertices from Three Midpoints
Find the original triangle vertices from all three side midpoints.
- Formula & worked example
- Private in your browser
- No signup
Calculator inputs
Loading calculator…
How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
Private by default
Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.
Formula and method
For the worked example, x = 0, y = 0, x = 4, y = 0, x = 0, y = 6.
A=M₁+M₃−M₂; B=M₁+M₂−M₃; C=M₂+M₃−M₁
Worked example
Enter these known values and leave the other values blank.
- X1
- 2
- Y1
- 0
- X2
- 2
- Y2
- 3
- X3
- 0
- Y3
- 3
- x
- 0
- y
- 0
- x
- 4
- y
- 0
- x
- 0
- y
- 6
Assumptions and limitations
- The three input points represent AB, BC and CA midpoints in that order.
- All coordinates share one scale and origin. Collinear midpoints describe a degenerate triangle.
Common questions
How do I use this relation?
Choose the relevant mode and enter independent known quantities. Leave a missing value empty where the control permits an inverse.
What do the displayed numbers mean?
The result follows the stated mathematical model. All dimensions must use consistent units; available unit selectors handle conversions.
References
Bookify validates the real geometric or algebraic domain and inverse branches omitted or approximated by this capture.
Related calculators
Explore algebra and geometric relations or browse all math calculators.