First answer is correct because angles DAB and EAD equal 180 degrees (supplementary)
1/8 divided by 3/4 is (1/8) / (3/4). When you divide fractions, you flip the 2nd number and change the divide into multiply. So (1/8)*(4/3). Multiply top by top and bottom by bottom to get 4/24. That simplifies to 1/6
