Question

Find the length indicated.

Answer 1

The length of
`BC` is
`3` units.

Explanation:

The points
`A,B,C` are collinear and
`B` is in middle of
`A,C`, so the expression that can justify the given statement is,

`AB+BC=AC`

The given values are,

`\begin{aligned}AB&=10\\AC&=13\end{aligned}`

Substituting values in the expression, it becomes,

`\begin{aligned}AB+BC&=AC\\10+BC&=13\\BC&=13-10\\BC&=3\end{aligned}`