Applet allows for the student to readily discover or meaningfully recall that when the altitude is drawn to the hypotenuse of a right triangle, it splits that triangle into 2 smaller triangles that are similar to the original triangle and to each other. The AA~ reasoning is visually manifested within this applet.
This is a great discovery lesson for using the the sum of the interior angles of a triangle to figure out and apply the concept of the sum of the interior angles of other polygons. It is aligned with CCSS.5.G.B.4.
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