Two equilateral triangles of side $10\sqrt{3}$ cm are joined to form a quadrilateral. What is the altitude of the quadrilateral?

12 cm 14 cm 16 cm 15 cm

15 cm

We know, Height of triangle = Height of quadrilateral Height of the quadrilateral = \(\frac{\sqrt {3}}{2}\) × a = \(\frac{\sqrt {3}}{2}\) × 10\(\sqrt {3}\) = 15 cm