Answer:
perimeter of a triangles are 12cm and 29cm respectively.
Step-by-step explanation:
finding the perimeter of a triangle simply means that you are finding the distance around. The simplest way to find the perimeter of a triangle is to sum up all its sides.
mathematically,
perimeter of a triangle = side A + side B + side C
perimeter of a triangle = 3cm + 4cm + 5cm
perimeter of a triangle = 12cm
for the second triangle according to the question
it says the triangle has sides, 7cm, 10cm, 12cm
perimeter of a triangle = 7cm + 10cm+ 12cm
perimeter of a triangle = 29cm
