1.3. Angles and Measurement http://www.ck12.org
Solution:
AD⊥
←→
FC
m^6 ADB=m^6 BDC=m^6 F DE= 45 ◦
AD=DE
F D=DB=DC
m^6 ADF=m^6 ADC= 90 ◦Angle Addition Postulate
Much like the Segment Addition Postulate, there is an Angle Addition Postulate.
Angle Addition Postulate:IfBis on the interior of^6 ADC, thenm^6 ADC=m^6 ADB+m^6 BDC. See the picture
below.
Example 9:What ism^6 QRTin the diagram below?