Question

student belcher, cash
properties of parallelograms
solve for the unknown variable (x).
answer: round to whatever you see in the problem.
ok

Explanation:

Step1: Use property of parallelogram

In a parallelogram, opposite angles are equal. So, $\angle F=\angle D$.

Step2: Set up equation

We have $2x + 18=40$.

Step3: Solve for $x$

Subtract $18$ from both sides: $2x=40 - 18$. So, $2x=22$.
Divide both sides by $2$: $x=\frac{22}{2}=11$.

Answer:

$11$