The three points of intersection of the adjacent angle
trisectors of any triangle ABC form an equilateral triangle DEF
called Morley's triangle.
Morley center is the intersection point of AE, BF and CD.

Hint to interact with the
figure (below): Click the
red button ()
on the figure to start the animation.
Drag points A, C and line AC to change
the figure. Press P and click the left mouse button to start the step by step construction.

Intersection of two lines is
the point at which they concur.
Angle trisector are two line that divide an angle in three
equal parts.

Equilateral triangle is a triangle with all three sides
of equal length.

Frank Morley (1860 – 1937) was a leading mathematician, known
mostly for his research into algebra and geometry. Among his
accomplishments was his discovery and proof of the celebrated
Morley's trisector theorem in elementary plane geometry, one
of the most striking theorems in triangle geometry. Frank
Morley was a member of Haverford College's Department of
Mathematics in the early part of the twentieth century.

Dynamic Geometry: You can alter the figure above
dynamically in order to test and prove (or disproved)
conjectures and gain mathematical insight that is less
readily available with static drawings by hand.

This page uses the
TracenPoche
dynamic geometry software and requires
Adobe Flash player 7 or higher.
TracenPoche is a project of Sesamath, an association of French
teachers of mathematics.

Instruction to explore the
illustration above:

Animation. Click the red
button
to start/stop animation

Manipulate. Drag points A
and C, and line AC to change the figure.

Step-by-Step construction.
Press P and click the left mouse
button
on any free area to show the
step-by-step bar and click 'Next
Step' button ()
to start the construction step-by-step:

Hide the step-by-step bar by
using again the combination P +
click left mouse.