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Altitude and area of a triangle. h = a * (square root of 3) / 2. h = a^2 * (square root of 3) / 4. Angles in a triangle. Angles in a triangle. The altitudes in equilateral triangle intersect at one point. The point of interesection divides altitude into line segments in the ratio 2 : 1. x = 2/3 * h, y = 1/3 * h, x/y = 2/1.