Theorems and Postulates for Congruent Triangles
The goal of this dynamic worksheet is to explore the
theorems for congruent triangles.
 First you need to learn how this applet works. Click on
some angles and sides of the given triangle ABC. When an element of
the triangle
is selected it will change its color and a free congruent element will
appear to the right of triangle ABC.
The free elements to the right have the
functionalities listed below. Try each of them.
 The segments can be moved to a different location on the
screen by
dragging the solid point.
 The segments can be rotated by dragging the empty point.
 You can construct a circle with center at the solid point
and a radius equal to the
length of the segment by clicking the
empty point.
 The angles can be moved to a different location by dragging
the thicker
side.
 The angles can be rotated by dragging the empty point or
the vertex.
 The sides of the angles can be extended by dragging the endpoints.
 Constructions:
 Select three elements of the given triangle ABC (any
combination of
sides and angles) by clicking on them.
 Using these elements try to construct a triangle
congruent to the
given triangle ABC.
 If your construction has sides parallel to the
corresponding sides of the given triangle, you can check your
construction by dragging triangle ABC over the
constructed
triangle.
 Will all possible combinations of three elements work?
 There are detailed instructions and videos below the applet.
Irina Boyadzhiev, Created with
GeoGebra
