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Find the area of an equilateral triangl...

Find the area of an equilateral triangle in which length of perpendicular on sides from a point D inside the `Delta ` are `2 sqrt(3) + 3 sqrt(3) and 5 sqrt 3 `

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To find the area of the equilateral triangle given the lengths of the perpendiculars from a point inside the triangle, we can follow these steps: ### Step 1: Understand the Problem We have an equilateral triangle \( ABC \) and a point \( D \) inside it. The lengths of the perpendiculars from point \( D \) to the sides \( AB \), \( BC \), and \( CA \) are given as \( h_1 = 2\sqrt{3} \), \( h_2 = 3\sqrt{3} \), and \( h_3 = 5\sqrt{3} \). ### Step 2: Use the Area Formula The area \( A \) of triangle \( ABC \) can be expressed in terms of the side length \( a \) of the equilateral triangle and the heights from point \( D \) to the sides: \[ A = \frac{1}{2} \times a \times h_1 + \frac{1}{2} \times a \times h_2 + \frac{1}{2} \times a \times h_3 \] This can be simplified to: \[ A = \frac{a}{2} (h_1 + h_2 + h_3) \] ### Step 3: Substitute the Values Now, substitute the values of the heights: \[ A = \frac{a}{2} (2\sqrt{3} + 3\sqrt{3} + 5\sqrt{3}) \] Calculating the sum of the heights: \[ h_1 + h_2 + h_3 = 2\sqrt{3} + 3\sqrt{3} + 5\sqrt{3} = (2 + 3 + 5)\sqrt{3} = 10\sqrt{3} \] So, we have: \[ A = \frac{a}{2} \times 10\sqrt{3} = 5a\sqrt{3} \] ### Step 4: Relate the Area to the Side Length The area of an equilateral triangle can also be expressed as: \[ A = \frac{\sqrt{3}}{4} a^2 \] ### Step 5: Set the Two Area Expressions Equal Now, we can set the two expressions for the area equal to each other: \[ 5a\sqrt{3} = \frac{\sqrt{3}}{4} a^2 \] ### Step 6: Solve for \( a \) To eliminate \( \sqrt{3} \) from both sides, we divide by \( \sqrt{3} \): \[ 5a = \frac{1}{4} a^2 \] Multiplying both sides by 4 gives: \[ 20a = a^2 \] Rearranging gives: \[ a^2 - 20a = 0 \] Factoring out \( a \): \[ a(a - 20) = 0 \] Thus, \( a = 0 \) or \( a = 20 \). Since \( a \) represents the side length of the triangle, we take \( a = 20 \). ### Step 7: Calculate the Area Now we can find the area of the equilateral triangle: \[ A = \frac{\sqrt{3}}{4} a^2 = \frac{\sqrt{3}}{4} (20^2) = \frac{\sqrt{3}}{4} \times 400 = 100\sqrt{3} \] ### Final Answer The area of the equilateral triangle is: \[ \boxed{100\sqrt{3}} \]
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