All you have to do is to reverse the order of the x and y components of (7,2):
(2,7).
Given:
The equation is:

To find:
The logarithmic equation that is equivalent to the given exponential equation.
Solution:
According to the property of logarithm:

We have,

Here,
. By using the above property of logarithm, we get


Therefore, the correct option is C.
Your possible triangles are:
20°, 80°, 50°