Question

D and E are the mid point of the sides AB & AC
respectively of a triangle ABC. If BC = 10 cm find DE​

Answer 1

Step-by-step explanation:

Given: D and E are mid points of AB and BC respectively. DF∥BC

Since, DF∥BC D is mid point of AB

By converse of mid point theorem, F is mid point of AC and DF=21BC (I)

Now, E and F are mid points of BC and AC respectively.Thus, by mid point theorem,

EF∥AB or EF∥DB

Since, opposite sides are parallel to each other. Hence, DBEF is a parallelogram

Perimeter of parallelogram = 2(BE+BD) (Opposite sides of parallelogram are equal)

Perimeter of parallelogram = 2(BE+21AB) (D is mid point of AB)

Perimeter of parallelogram = 2BE+AB

Perimeter of parallelogram = 2×(8.4)+10

Perimeter of parallelogram = 26.8 cm