A horizontal line has points D, B, C. A line extends vertically from point B to point A. Given that Ray B A bisects ∠DBC, which statement must be true?
a) m∠ABD = m∠ABC
b) AB ≅ BC
c) B is the midpoint of DC.
d) m∠DBC = 90°

  a) m∠ABD = m∠ABC

Step-by-step explanation:

The meaning of angle bisector is that each of the created angles is congruent to the other:

  m∠ABD = m∠ABC

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is