How do you do this with decimals

x=102

Steps:

This is an isosceles triangle which mean 2 angles and 2 sides are congruent. In this case, the 3.3 sides corresponds to the 39 degree angle. This means that the other angle next to x angle is also 39 degrees.

39+39= 78

All the angles in the triangle needs to equal 180.

So subtract 78 from 180 to find the degree of x angle.

180-78= 102