At IDNLearn.com, find answers to your most pressing questions from experts and enthusiasts alike. Discover the information you need quickly and easily with our reliable and thorough Q&A platform.
Step-by-step explanation:
m L DBC = 90-20 = 70°
m L DCB = 20°
m L CDB = 90°
m L ACD = 90-20 = 70°
m L ADC = 90°