Triangles ABC and DEP are equal. What is the perimeter of triangle DEP if AB = 3cm, BC = 4cm, CA = 5cm?

By hypothesis, our triangles abc and dep are equal, then it follows from this that since our triangles are equal, then their sides will also be equal.
Therefore: BC = DE = 3 cm, BC = EP = 4 cm, CA = PD = 5 cm.
In order to find the perimeter (P) we use the formula for finding the perimeter (P).
P = a + b + c
We substitute our data: P (dep) = de + ep + pd.
P = 3 + 4 + 5 = 12 (cm).
Answer: the perimeter is twelve centimeters.