Final answer:
To find the measure of ∠CDE, set up an equation by using the fact that the sum of the angles in a triangle is 180°. Solve for x, and substitute the value back into the expression for ∠CDE.
Step-by-step explanation:
To find the measure of ∠CDE, we need to use the fact that the sum of the angles in a triangle is 180°. We can start by setting up an equation:
(2x + 10)° + (x + 1)° + (6x - 13)° = 180°
Combining like terms:
9x - 2 = 180°
Adding 2 to both sides:
9x = 182°
Dividing both sides by 9:
x = 20.22°
Now, we can substitute this value back into the expression for ∠CDE to find its measure:
(6(20.22) - 13)° = 107.32°