Question

the measure of angle $abc$ is $145^{circ}$. the measure of angle $abd$ is $115^{circ}$. the measure of angle $dbc$ is $x^{circ}$. find the value of $x$.

Explanation:

Step1: Identify angle - relationship

We know that $\angle ABC=\angle ABD + \angle DBC$.

Step2: Substitute given values

Substituting $\angle ABC = 145^{\circ}$, $\angle ABD=115^{\circ}$ and $\angle DBC = x^{\circ}$ into the equation, we get $145 = 115+x$.

Step3: Solve for x

Subtract 115 from both sides of the equation: $x=145 - 115$.
$x = 30$.

Answer:

$30$