If two medians BE and CF of a triangle ABC, intersect each other at G and if BG = CG, ∠BGC = 60° and BC = 8 cm then area of the triangle ABC is
In Δ BGC
∠BGC = 60° and BG = GC
$$\therefore$$ ΔBGC is an isosceles triangle
∠GBC = ∠GCB
As, we know sum of angles of a triangle = 180°
$$\therefore$$ ∠GBC + ∠GCB + ∠BGC = 180°
=> 2∠GBC = 180° - 60°
=> ∠GBC = 120°/2 = 60°
∠GBC = ∠GCB = ∠BGC = 60°
$$\therefore$$ ΔGBC is equilateral triangle
Area of equilateral triangle = $$\frac{\sqrt{3}}{4} * side^2$$
Area of $$\triangle$$GBC = $$\frac{\sqrt{3}}{4} * 8^2$$
= 16$$\sqrt{3}$$
Median of triangle divides the triangle into two parts of equal area.
3 medians of a triangle divide the triangle into six parts of equal area.
$$\therefore$$ Area of ΔGBC = 2 × area of ΔGDC
Area of ΔABC = 6 × area of ΔGDC
= 3 × 2 × ΔGDC
= 3 × area of ΔGBC
= 3 × 16$$\sqrt{3}$$
= 48$$\sqrt{3} cm^2$$
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