Answer:
The measure of ∠BDA is 30 Degrees.
Step-by-step explanation:
Lets construct a trapezium with the given data
If O is the point of intersection of the diagonals, ∆ AOD ~ ∆COB. Then
On substituting the given values
Also we know that AC = 6 . That is
AO + OC = 6 or OC = 6 - AO
substituting for CO and cross multiply
5·AO = (6-AO)·7
5AO = 42 - 7AO
12AO = 42
AO = = 3.5
All of the angles at E are right angles, so has the trigonometric ratio
= = 0.5 =
∠BDA = arcsin(1/2) = 30°