### Home > MC2 > Chapter 3 > Lesson 3.1.3 > Problem3-29

3-29.

Find the perimeter of each figure made of algebra tiles below.

1. Refer to the solutions for 3-20 or the Math Notes box of Lesson 3.1.3.

Remember, the tiny square represents a unit piece, which is a $1 × 1$ square.

$4x + 4$

1. Refer to the solutions for 3-20 or the Math Notes box of Lesson 3.1.3.

Since part of the side with length $x$ touches the unit square, the side that is included in the calculation of the perimeter is $x −1$.

Do you understand why the length of one side is labeled
$x -1$?

1. Refer to the solutions for 3-20 or the Math Notes box of Lesson 3.1.3.