Answer:
B= 90
C= 80
D= 100
Step-by-step explanation:
So let’s start with the bottom angles.
We know that the adjacent angles in a parallelogram add up to 180° so our equation would be . So let’s simplify it b and b are both the same variables so we will get 2b and -10 + 10 is 0 so we get the following equation
.
So now we divide 180 and 2 and we get 90 as b.
So one side will be 100 because of the +10 and the other 90 because of the -10.
Now for the next side.
So we know that b+10 is adjacent to c so 180-100 is 80, so 80 is c.
Now for d.
b-10 is 80 so 180-80 is 100, so d is 100.