Question

Can someone help me with 3 a and b?? Thank you

Answer 1

M∠ADB + m∠BDC = m∠ADC   [angle addition postulate]

x + x + 10 = 60 
2x + 10 = 60
2x = 60 - 10
2x = 50
x = 50/2
x = 25

a
m∠ADB = x = 25°

b 
m∠BDC = x + 10 = 25 + 10 = 35°