Answer:
1. Write the addition of "a", "b" and "c".
2. The equation is:
![P=a+b+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/oftjeyabl1g7s2iex4uvl56u76hn2q52m6.png)
Explanation:
You know that P represents the perimeter of the triangle and a, b and c represent the sides of the triangle.
By definition, the sum is the result of an addition. Therefore, the statement "The perimeter P of a triangle is equal to the sum of the lengths of sides a, b, and c”, indicates that the perimeter is obtained by adding the lengths of the sides of the triangle.
Knowing this, you can write the following equation:
![P=a+b+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/oftjeyabl1g7s2iex4uvl56u76hn2q52m6.png)