PLS HELP!! Can I also get a step by step explaination?

m∠abd = m∠dbc

step-by-step explanation:

given : ab bisects ∠dbc

as we know that bisection means ab divides   ∠dbc   in two equal angles named as   ∠dba and   ∠abc

so, m∠abd = m∠dbc  

because ab bisects ∠dbc.

hence , the first statement m∠abd = m∠dbc is true.

example answer: "to determine if a sum is reasonable you can round each number to the nearest whole and compare the estimated sum to the actual sum."

hope this you and anyone else who needs the answer : ^)