1. given
2. measure angle 1 plus measure angle 2 equals 90 degrees
3. B D bisects angle A D C
4. definition of angle bisector
5. definition of congruence
6. measure angle 1 is equal to measure angle 3
7. angle 1 is congruent to angle 3
7. definition of congruence
hope that helps
Answer: i think 1/4
Step-by-step explanation: maybe i might be incorrect
40s=360+30a
40s+30a=$3960
40s=360+30a
40s/40=360+30a/40
s = 9+3/4a
40(9+3/4a) +30a=$3960
360+30a+30a=$3960
360+60a=$3960
360-360+60a=$3960
60a=$3960
60a/60 = $3960/60
a= $60
The algebra book is $60
Here is the correct answer along with the way i got it! I hope this helps :)
