The perimeter of the rectangle is 46 cm. Its length is 20 cm. What is the width?

To find the width of a rectangle, we will compose and solve a linear equation, for this we will use the formula to find the perimeter of a rectangle.
Let’s start by recalling the formula for finding the perimeter:
P = 2 (a + b);
From the condition it is known that the perimeter of the rectangle is 46 cm.And its length is also known – 20 cm.
Let us denote the width of the rectangle using the variable x cm and compose the equation:
2 (20 + x) = 46;
20 + x = 46: 2;
20 + x = 23;
x = 23 – 20;
x = 3 cm.
Answer: 3 cm width of the rectangle.