Question

find the perimeter. include the unit.

Explanation:

Step1: Recall perimeter formula

The perimeter \(P\) of a triangle is the sum of the lengths of its sides. If the side - lengths are \(a\), \(b\), and \(c\), then \(P=a + b + c\).

Step2: Identify side - lengths

Here, \(a = 9\mathrm{cm}\), \(b = 11\mathrm{cm}\), and \(c = 13\mathrm{cm}\).

Step3: Calculate perimeter

\(P=9 + 11+13=33\mathrm{cm}\)

Answer:

33 cm