BD bisects ABC, m/ABC =8x, m/ABD=2x + 30. Find m/DBC.

Answer:

Step-by-step explanation:

To find the measure of angle DBC, we can use the angle bisector theorem, which states that in a triangle, if a line bisects one of the angles, it divides the opposite side into segments proportional to the other two sides. In this case, BD bisects angle ABC, so:m∠ABD / m∠DBC = AB / BCWe are given:

m∠ABC = 8x

m∠ABD = 2x + 30So, we have:(2x + 30) / m∠DBC = AB / BCNow, we need to express AB / BC in terms of x. To do that, we'll use the fact that angles in a triangle add up to 180 degrees:m∠ABC + m∠ABD + m∠DBC = 180Substitute the given angle measures:8x + (2x + 30) + m∠DBC = 180Combine like terms:10x + 30 + m∠DBC = 180Now, isolate m∠DBC:m∠DBC = 180 - 10x - 30

m∠DBC = 150 - 10xNow, we can substitute this expression for m∠DBC back into our proportion:(2x + 30) / (150 - 10x) = AB / BCNow, you can solve for m∠DBC:Cross-multiply:(2x + 30)(BC) = (150 - 10x)(AB)Now, you would need more information about the relationship between AB and BC or additional angle measures to solve for the exact value of m∠DBC. Without that additional information, you can't determine the specific angle measure.