Question

In $△$ ABC , D and E are mid-point of AB and AC, AD = 3.5 cm, AE = 4 cm, DE = 2.5 cm. Find perimeter of $△$ ABC.

Answer 1

R.E.F image

$AB=2AD$ (AD is the mid point of AB)

$AB=2\times 3.5cm$

$AB=7cm$

$AC=2AE$

$AC=2\times 4cm$

$AC=8cm$

$BC=2DE$ (Midpoint Theorem)

$BC=2\times 2.5cm$

$BC=5cm$

Perimeter $=AB+BC+CA$

$=7+5+8$

$=20cm$