20 points and brainliest if answered and explained! triangle abc has the angle measures shown. m∠a= (2x)° m∠b= (3x)° m∠c= (4x)° which statement is true about the angles? a) m∠a= 20° b) m∠b= 60° c) ∠a and ∠b are complementary d) m∠a+m∠c= 100°

What you need to know for this case is that the sum of the internal angles of a triangle is 180 °
 We then have the following equation that is given by:
 (2x) + (3x) + (4x) = 180
 Clearing x we have:
 9x = 180
 x = 180/9
 x = 20
 Therefore we have:
 m∠A = (40) °
 m∠B = (60) °
 m∠C = (80) °
 
 B) m∠B = 60 °