given that bisects ∠dbc, which statement must be true?
m∠abd = m∠abc
ab ≅ bc
b is the midpoint of dc.
m∠dbc = 90°

Only statement 1 is true.

Step-by-step explanation:

It can be clearly seen that the the points D, B, and C lie on the straight line. Therefore, the angle DBC must be 180 degrees. This means that the fourth statement is false. If a line is cutting an angle right in the middle, that line is called an angle bisector. It can be seen in the diagram that the line AB is bisecting the able DBC. Since the angle bisector equally cuts the angle, therefore the angles ABD and ABC are equal. So angle ABD = angle ABC = 180 degrees / 2 = 90 degrees. So the first option is correct. The second statement is false because the angle bisector can start from any point in the plane. This means that its length is ambiguous. Same is the case for the line BC. Statement 3 is true if the line AB acts as a perpendicular bisector as well, other than the angle bisector. Just like latter, former equally cuts the line from the middle. If the line AB is not a perpendicular bisector, then statement 3 is not true. If the line AB is a perpendicular bisector, then statement 3 is true!!!

- both graphs increase on their domain.

- the graphs of both functions have the same x-intercept.

- neither graph has a y-intercept.