Tatami mats are a floor covering used in japan. tatami mats are equal in size unless they are cut in half. the floor shown has an area of 81square ft and is covered with 4.5 tatami mats. what is the lengh of one tatami mat if it has a width of 3feet

As per the question we can see that floor has the area of 81 square feet and is covered with 4.5 tatami mats.

First of all we will use unitary method to find out how much area does each mat cover.

Unitary method is a way of finding the value of a single unit, and then finding the necessary value by multiplying the single unit value.

Now,

4.5 mats cover 81 square feet.

1 mat will cover square feet.

Now, lets say that the length of each tatami mat is 'x' feet. We have been given that the width of the mat is 3 feet.

Now, the area of each mat which we just calculated is 18 square feet should also be equal to

So,

Solving for 'x' we get:

We had assumed that 'x' is the length of the tatami mat, therefore, the length of one tatami mat is 6 feet.