Answer:
m of angle A is 60 degrees, m of angle B is 80 degrees, and m of angle C is 40 degrees
Step-by-step explanation:
Given: BD=DC, this means the triangle BDC is isoceles because of the two equal sides.
Using the base angles Thereom we can tell that m of angle C is equal to m of angle 2.
Given that m of angle BDC is 100 degrees, using sum of angles in triangle we develop the equation
m of angle C= 180-100-angle 2
since angle 2 is equal to angle C we see that they are bothe equal to 40 degrees.
Now for B, we can easily tell it is 80 degrees since we found that angle 2 is 40 degrees and angle 1 is equal to angle 2 40+40=80 degrees
Lastly, for A we can tell it is 60 degrees, the reason is we found angle 1 is 40 degrees and we know that BDA=80 using supplemantary angles to BDC.
Develop the equation A=180-(80+40)=60 degrees