Angle 2=3, so angle 1=4 because angles ABC & BCD equal 90°. When you add together the angles of a triangle you get 180 and if you could put angle 1 and 4 together it would look like an upward version.
That is the best way I could describe it. Hope that helps.
Answer:
Step-by-step explanation: make sure that a+b=180
for you'll get the answer
I'm pretty sure it is 20 hundreths
You transfer the .5 and .5 is half so the answer is 1/2
