Final answer:
To find the measure of angle EBC, we can use the fact that the angles in a triangle add up to 180 degrees. By setting up an equation and solving for x, we can find the value of x and then substitute it back into the equation to find the measure of angle EBC. The measure of angle EBC is 37.7 degrees.
Step-by-step explanation:
To find the measure of angle EBC, we can use the fact that the angles in a triangle add up to 180 degrees. Therefore, we have:
angle DBC + angle DBE + angle EBC = 180
Substituting the given measures:
(12x - 3) + (5x + 12) + (3x + 13) = 180
Combine like terms:
20x + 22 = 180
Subtract 22 from both sides:
20x = 158
Divide by 20:
x = 7.9
Now we can substitute this value back into the equation to find the measure of angle EBC:
angle EBC = 3(7.9) + 13 = 24.7 + 13 = 37.7 degrees