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:

Answer:
Step-by-step explanation:
0,20
Answer:
143
Step-by-step explanation:
90-53=37
180-37=143
(3 - i) + (1 - 2i)
= 3 + 1 - i - 2i
= 4 - 3i