is equilateral with each side equal to 4 cm. What is the area this triangle if AD is the perpendicular bisector to side BC?
(E) None of the above
It is given to us that AD is the perpendicular bisector to side BC. Also, we have BC=4 cm.
Therefore, BD = 2 cm.
In , we have
Note that area of equilateral triangle is also
Hence, the answer is (D).