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Each of the equal sides of an isosceles triangle measures 2 cm more than its height, and the base of the triangle measures 12 cm. Find the area of the triangle. |
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Answer» Let h be the height, then Each of the equal sides of an isosceles triangle = (h + 2) cm and Base = 12 cm Area of a triangle = 1/2 × Base × Height = 1/2 x 12 x h ….(1) Area of isosceles triangle = 1/4 x b x √(4a2 – b2) = 1/2 x 12 x √(4(h+2)2 – 144) …(2) From (1) and (2), we get 1/2 x 12 x h = 1/2 x 12 x √(4(h+2)2 – 144) 6h = 3√(4h2 + 16h + 16-144) 2h = √(4h2 + 16h-128) 4h2 = 4h2 + 16h – 128 16h = 128 or h = 8 Height is 8 cm. Now, Area of a triangle = 1/2 × Base × Height = 1/2 × 12 cm × 8 cm = 1/2 × 96 cm2 = 48 cm2. Answer!! |
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