Answer:
a. m∡ADB = 25°
b. m∡BDC = 35°
c. Used angle addition postulate. It created the equation m∡ADB + m∡BDC = m∡ADC which helped solve for x°
Step-by-step explanation:
The angle addition postulate states the addition of smaller angles equals the overall angle OR m∡ADB + m∡BDC = m∡ADC
Given:
m∡ADB = x°
m∡BDC = x° + 10
m∡ADC = 60
m∡ADB + m∡BDC = m∡ADC; now substitute
x° + x° + 10 = 60
2x° = 50
x° = 25°; now plug back
m∡ADB = x° = 25°
m∡BDC = x° + 10 = 25° + 10° = 35°
I hope this helps
