Given :
In ∆ABC,
- ∠A = 60°
- ∠B = 60°
- BC = 12 units
- ∠BDC = 90°
To Find :
Solution :
As, we have :
So, By angle sum property of triangle :
∠A + ∠B + ∠C = 180°




Now, we have :
As, all angles are of same length, therefore it is a equilateral triangle.
We know that sides of equilateral triangle are equal.

Now, we have BC = 12 units.
Hence, all sides are of 12 units.
Now, we know that area of equilateral triangle is :





So, Area of given triangle is 36√3 units².