Geometry, please answer question ASAP

66

Step-by-step explanation:

since BD and BC are congruent, angle C and angle D are equal. this means 6x-9=3x+24. If you solve this equation you get x=11. If you plug it into either 6x-9 or 3x+24 you get 57. 180-(57+57)=66

19.side- angle- side

20. angle- side- angle

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116