Answer:
The perimeter of triangle ABC is 15.8 units
Explanation:
we know that
The perimeter of a triangle is equal to the sum of its three length sides
![P=AB+BC+AC](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b17c2aup6jerq8501zofznbgzrdnoiarpx.png)
the formula to calculate the distance between two points is equal to
we have the coordinates
![A(5,-1),B(-1,1),C(0,-3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gxjkwrjvcj1xuboplcab0hes17l072sb2v.png)
step 1
Find the distance AB
we have
![A(5,-1),B(-1,1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6ycyfesl6ry9gf29aa5d7grym500kprlw2.png)
substitute in the formula
step 2
Find the distance BC
we have
![B(-1,1),C(0,-3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/y11x19owj2iuimwv70hz1q01eaywlzirdb.png)
substitute in the formula
step 3
Find the distance AC
we have
![A(5,-1),C(0,-3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/famegx9cptfi8dz89cfq600fbbyt4lpaeo.png)
substitute in the formula
step 4
Find the perimeter
![P=AB+BC+AC](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b17c2aup6jerq8501zofznbgzrdnoiarpx.png)
substitute the values
![P=6.3+4.1+5.4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a1ilx988ciyv96207o1fzo787hdqixudli.png)
![P=15.8\ units](https://img.qammunity.org/2020/formulas/mathematics/middle-school/c8q269t160qaihpirilqptnxz2vf2zkeyn.png)