
Manipulative 1: Congruent Triangles.


Two geometric figures are congruent if they are the same
shape and size, but may be flipped,
moved, and/or rotated.^{[1]} If object
a is congruent with object b, we write a ≅ b and
say, "a is congruent with b."
Manipulative 1 shows two congruent triangles. Click on the points on the sliders and the
blue points on the triangles in the manipulative to change the figure. To place one triangle
over the other, set horizontal, vertical and rotation to 0 and uncheck the Flip checkbox.
