Its the third one for the answer
Answer:
1. Write the addition of "a", "b" and "c".
2. The equation is: 
Step-by-step explanation:
You know that <em>P</em> represents the perimeter of the triangle and <em>a, b </em>and <em>c </em>represent the sides of the triangle.
By definition, the sum is the result of an addition. Therefore, the statement "The perimeter <em>P</em> of a triangle is equal to the sum of the lengths of sides <em>a, b</em>, and <em>c</em>”, indicates that the perimeter is obtained by adding the lengths of the sides of the triangle.
Knowing this, you can write the following equation:

Given:
The number is
.
To find:
The a+bi form of given number.
Solution:
We have,

It can be written as

![[\because \sqrt{ab}=\sqrt{a}\sqrt{b}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csqrt%7Bab%7D%3D%5Csqrt%7Ba%7D%5Csqrt%7Bb%7D%5D)
![[\because \sqrt{-1}=i]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csqrt%7B-1%7D%3Di%5D)

Here, real part is missing. So, it can be taken as 0.

So, a = 0 and
.
Therefore, the a+bi form of given number is
.
Determining the scale for the horizontal (x) axis. When making a graph, you want to use as much of the "graph paper" as possible, and generally, you want each <span>division or space on the graph to represent a whole number that makes the plotting relatively easy, such as 5, 10, 25, 50, 100, etc. </span>I hope my answer has come to your help. God bless and have a nice day ahead!