Question

in triangle ABC ,D,EandF are the mid point of AB,BC and CA respectively . if AB =6cm,BC=7.2cm amd CA=7.8cm, then find out perimeter of triangle DEF​

Answer 1

Hi Frd

here, first we find the perimeter of triangle ABC
so,
perimeter of triangle = sum of all sides
= 6 cm + 7.2 cm + 7.8 cm
= 21 cm

Now,
perimeter of triangle DEF = 21 cm / 4
= 5.25 cm

my friend there is a property of triangle when the midpoints of all the sides of a triangle are joined together it makes a new Triangle so the perimeter of the newly formed Triangle will be half of the perimeter of the bigger Triangle.

and area of the newly formed triangle will be e one fourth of the area of bigger Triangle

Answer 2

the perimeter of triangle DEF is 21/4=5.25cm