Remark
You need to do some trig to get the final answer. There is no way around it. You can however, solve the first part with the Pythagorean Theorem.
Step One
Find AB
AB^2 = DB^2 + AD^2
AB^2 = 7.5^2 + 4.9^2
AB^2 = 56.25 + 24.01
AB^2 = 80.26
AB = sqrt(80.26)
AB = 8.9588
Step Two
Move to the triangle on your right. Find x
Tan(C)= opposite / adjacent
Tan(55.8) = AB/adjacent
Tan(55.8) = 8.9588/ x Multiply both sides by x
x * tan(55.8) = 8.9588 Divide by tan(55.8)
x = 8.9588/tan(55.8)
x = 6.09
Answer: A
