Online Geometry theorems, problems, solutions, and related topics.
Geometry ProblemClick the figure below to see the complete problem 559.ZoomLevel: High School, SAT Prep, College geometry
el angulo entre las bisectrices de dos angulos suplementarios es 90° y aquí, por llegar al incentro, tenemos bisectrices.
ADB/2 = (B1 + C)/2 and BDC/2 = (180 - B1 - C)/2=>ADB/2 + BDC/2 = 90I have sent yesterday solution for 558 (delete this )
angle EDB = (1/2)*angle BDA and angle BDF = (1/2)* angle BDC. adding the results we get angle EBD + angle BDF = angle EDF = (1/2)*(angle BDA + angle BDC) = (1/2)*angle ADC = (1/2)*180 degrees = 90 degrees. ADC is a straight line so angle ADC is 180 degrees. therefore angle EDF = 90 degrees.Q. E. D.
Since DF bisects < BFA and EF bisects < CFA the result is obviousSumith PeirisMoratuwaSri Lanka