Question

in an equiletral triangel ABC,Mand N are midpoints of sides AB andAC. if MN=5 find perimeter of ABC

Answer 1

Hey!!!!

Here M and N are midpoints is AB and AC thus we can use the famous class 9 mid point Theorem that is MN ll BC and BC = 2MN

Thus AB = BC = AC = 10cm

Perimeter = 3AB
=> 30cm

Hope this helps

Answer 2

Since it is an equilateral triangle
Therefore all iys sides are equal
AB = AC = BC
MN = 5cm
By mid point theroem MN = 1/2 BC
5 = 1/2 BC
BC = 10 cm
AB = BC = AC = 10 cm
Perimeter of triangle = 10 + 10 + 10 = 30cm

Hope it helps.