Question

What is the value of x given the following image?

Answer 1

The angle we are given, as a whole, is a right angle. That means angles CDF and FDE are complementary, or add up to 90 degrees.

CDF + FDE = 90

2x + (x + 9) = 90

3x + 9 = 90

3x = 81

x = 27

Answer: x = 27

Hope this helps!