Video Transcript
Write an algebraic expression for
the perimeter of the triangle below.
We begin by recalling that the
perimeter of a triangle is the sum of all its side lengths. We note that the base of the
triangle has a length that is the sum of two 𝑏 and five 𝑐, written two 𝑏 plus
five 𝑐. We can add all of the side lengths
together to get nine 𝑎 plus two 𝑏 plus five 𝑐 plus 10. Since addition is associative and
we can add these values in any order, we can remove the parentheses as shown. Hence, the perimeter of the
triangle is nine 𝑎 plus two 𝑏 plus five 𝑐 plus 10.
