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16) The three angles of a triangle are 11x – 1,4x + 15 and 20x – 9. Find the measure of all the angles of the triangle. * a) 55, 35,92b) 54,35,91c) 56,32,78d) 66,33,91* |
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Answer» 11x - 1 2nd∠ = 4x + 15 3rd ∠ = 20x - 9as we KNOW that sumof all angle of triangle = 180° so , (20x - 9) + (11x - 1) + (4x + 15) = 180 20x - 9 + 11x - 1 + 4x + 15 = 180 20x + 11x + 4x = 180 + 9 + 1 - 15 35x = 180 - 5 35x = 175 x = 175 / 35 x = 5 1st∠ = 11x - 1 = 11 × 5 - 1 = 55 - 1 = 54°2nd∠ = 4x + 15 = 4 × 5 + 15 = 20 + 15 = 35°3rd ∠ = 20x - 9 = 20 × 5 - 9 = 100 - 9 = 91° Option 'B' is correct . |
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