Answer:
b. 12 cm
Explanation:
The perimeter of any shape is the sum of the lengths of its sides.
We can call the three sides of a triangle a, b, and c. Thus, the perimeter, P is given by the formula:
P = a + b + c
Thus, we can plug in 3 for a, 4 for b, and 5 for c to find P, the perimeter of the triangle in centimeters:
P = 3 + 4 + 5
P = 7 + 5
P = 12
Thus, the perimeter is 12 cm (answer b.).