The midpoints D and E of the sides AB and AC of an equilateral triangle are joined together to form a line segment DE. If AD = 4cm, then find DE.
4
ABC is an equilateral traingle. And AD = 4
Since D is the midpoint of AB,
AB=2×AD=8 cm.
Since, it is given that ABC is an equilateral triangle; all sides are equal to 8 cm.
Now, using midpoint theorem, we can say that DE = 12 BC = 4 cm.