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:

For this case we must complete squares:

We add the square of half the coefficient of the term "x",
on both sides of the equation:

According to the perfect square trinomial we have:

Rewriting the expression we have:

ANswer:

the coordinates are (-2,1) (-2,-3) that is the answer
Answer:25
Step-by-step explanation: