Final answer:
To given measure of angle F, we apply the rule that the sum of angles in a triangle equals 180 degrees. Solving for x, we then substitute this value into the expression for F finding F is approximately 48 degrees.
Step-by-step explanation:
From the given angles at E, D and F, we understand that these are the angles of a triangle and the sum of the measures of the angles in a triangle is 180°. This allows us to create the equation 8x - 18 + 6x - 4 + 5x - 7 = 180. When we simplify this, we get 19x - 29 = 180, and solving for x gives us x = approx 11. If we substitute x in the expression for angle F (5x-7), we get F ≈ 48°.
Learn more about Angles in a Triangle