It is true, how??Here is explanation:
Consider a quadrilateral ABCD .Join diagnol AC so two triangles ABC & ACD will form.
Sum of interior angles of ABC is 180 and that of ACD is 180 as well.So, the total sum of the interior angles of ABC & ACD is 360 which is the sum of interior angles of quadrilateral itself.
Is there more context to the question?
Given:
The expression is

To find:
The equivalent expression.
Solution:
Distributive property of multiplication over addition is

Where, a, b and c are real numbers.
We have,

Using distributive property, we get


Therefore, the expression
is equivalent to the given expression.
Solution
The dimension of the rectangular floor is 18ft long and 12 ft wide
Using the conversion table
It is given that 1yd =3 ft
This shows that
12 feet will be equivalent to

Also 18ft will be equialent to

Therefore the new dimension is 6 yard by 4 yard
The area will be

Therefore the required area is