In the diagram, bisects ABC. Find mABD and mDBC

Angle ABD =  45 degrees

Angle DBC =  45 degrees

Step-by-step explanation:

If the ray BD bisects ABC, then it divides it in two angles of equal measure. The we can write the following equality:

angle ABD = Angle DBC

9 x + 9 = 12 x - 3

solve for x by subtracting 9x from both sides,

9 = 3 x - 3

and adding 3 to both sides:

9 + 3 = 3 x

12 = 3 x

divide both side by 3 to isolate "x":

12/3 = x

x = 4

And now we can find the value of each angle:

Angle ABD = 9 x + 9 = 9 (4) + 9 = 36 + 9 = 45 degrees

Angle DBC = 12 x - 3 = 12 (4) - 3 = 18 - 3 = 45 degrees

1.3

step-by-step explanation:

3x2=6   9x+6

bring down the 6 on both sides

6+6=12

12= 9x

divide by 9

12/9 =

1.3 =x

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)