Problem:
Two square tiles, each of length 10 cm, are placed side by side to form a rectangle. What is the perimeter of the rectangle?

Solution:
To find the perimeter of the rectangle, we need to understand the concept of perimeter and how it relates to the given problem.

Definition:
Perimeter is the distance around the outside of a shape. It is the sum of all the sides of the shape.

Given Information:
- Two square tiles are placed side by side.
- Each square tile has a length of 10 cm.

Understanding the problem:
In the given problem, two square tiles are placed side by side, forming a rectangle. Since the tiles are squares, all sides of each tile are of equal length. Therefore, the length of each side of the square tile is 10 cm.

Key Points:
- Two square tiles are placed side by side.
- Each square tile has a length of 10 cm.

Calculating the Perimeter:
To find the perimeter of the rectangle formed by the two square tiles, we need to determine the length and width of the rectangle.

Since the tiles are placed side by side, the length of the rectangle is equal to the combined length of the two tiles. Therefore, the length of the rectangle is 10 cm + 10 cm = 20 cm.

Since the tiles are placed side by side, the width of the rectangle is equal to the length of each tile. Therefore, the width of the rectangle is 10 cm.

Now, we can calculate the perimeter of the rectangle using the formula:
Perimeter = 2 * (Length + Width)

Substituting the values, we get:
Perimeter = 2 * (20 cm + 10 cm)
Perimeter = 2 * 30 cm
Perimeter = 60 cm

Therefore, the perimeter of the rectangle formed by the two square tiles is 60 cm.

Summary:
The perimeter of the rectangle formed by two square tiles, each with a length of 10 cm, is 60 cm. Perimeter is the distance around the outside of a shape and is calculated by adding up all the sides of the shape.