In order to find the surface area of a rectangle:
-- Find or measure the length of the rectangle.
-- Find or measure the width of the rectangle.
-- Make sure both quantities are in the same units.
If they're not, then convert one or the other so that they are.
-- Multiply the two numbers.
The product is the area of the rectangle, in units of
square-(the unit in which the dimensions are measured).
How can i help you .what is your question
Answer:
<h2>54m²</h2>
Step-by-step explanation:
<h3>METHOD 1:</h3>
You can use the Heron's formula:

where
<em>p</em><em> - half of perimeter</em>
<em>a, b, c</em><em> - lengths of sides</em>
We have

Calculate:

<h3>METHOD 2:</h3>
Let's check that it is not a right triangle.
If the sum of the squares of the two shorter sides is equal to the square of the longest side, then this triangle is rectangular.
We have

Check:

This is a right trianglr wherew 9m and 12m are legs and 15m is a hypotenuse.
The formula of an area of a right triangle is:

<em>a, b</em><em> - legs</em>
Substitute:

What are the options to check off?