Answer: x = 53
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Step-by-step explanation:
Sides ED and FD are the same length due to the red tickmarks.
The angles opposite these side lengths, angle E and angle F, are congruent as well. So angle F is also x.
For any triangle, the three angles always add to 180
F+E+D = 180
x+x+74 = 180
2x+74 = 180
2x+74-74 = 180-74 .... subtract 74 from both sides
2x = 106
2x/2 = 106/2 ... divide both sides by 2
x = 53
As a check,
F+E+D = x+x+74 = 53+53+74 = 180
which verifies the answer.