GeometricScene[{{A.,B.,C.,D.},{}},{Triangle[{A.,C.,B.}],PlanarAngle[{A.,C.,B.}]90°,GeometricAssertion[{Line[{{A.,D.,B.},{C.,D.}}]},"Perpendicular"]},{GeometricAssertion[{Triangle[{A.,C.,D.}],Triangle[{C.,B.,D.}],Triangle[{A.,B.,C.}]},"Similar"]}]