To find the expression for the perimeter of the given quadrilateral, we need to add up the lengths of all the sides. The lengths of the sides are given as:

• $2n - 5$
• $3n - 4$
• $n + 3$
• $2n + 1$

Step 1: Write the perimeter expression

The perimeter $P$ is the sum of all sides:

$P = (2n - 5) + (3n - 4) + (n + 3) + (2n + 1)$

Step 2: Simplify the expression

Now, combine like terms:

$P = (2n + 3n + n + 2n) + (-5 - 4 + 3 + 1)$

$P = 8n - 5$

Step 3: Evaluate when $n = 4$

Substitute $n = 4$ into the simplified expression:

$P = 8(4) - 5 = 32 - 5 = 27$

Thus, the perimeter of the figure when $n = 4$ is 27 units.

Would you like more details on the steps, or do you have any questions?

Here are 5 related questions you could explore:

1. How would the perimeter change if one of the side expressions was doubled?
2. Can you find the perimeter if $n = 5$?
3. What is the perimeter of a square with side length $3n - 4$?
4. How do different values of $n$ affect the shape of this quadrilateral?
5. Can you solve for the area of this quadrilateral with the given side lengths?

Tip: Always simplify algebraic expressions step by step, combining like terms carefully to avoid errors.