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A triangle with integral sides has perimeter 8 unitsThe area of the triangle is____sq u1) 2(2) 2√2(4) 3(3) 3√2 |
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Answer» Let integral sides of triangle be a, b, c a + b + c = 8 => a + b = 8 - c => sum of 2 sides a+ b = 8–1 =7 a+ b = 8 - 2 = 6 a + b = 8- 3 = 5 a+ b can not be 4, 3, 2, or 1 ( as the sum of 2 sides > third side) . & perimeter given is 8. Out of sums given above, only possible sum will be 6 or 5 Reason: If sum a+ b = 7 , sides a, b, c are to be 6, 1, 1 or 5,2 , 1or 4, 3, 1 which are not possible. As the sum of any 2 sides of a triangle > third side. If a + b = 6, sides a,b,c are to be 5,1,2 or 4, 2, 2 or 3,3,2 . First 2 triplets won't be possible. The same reason as given above. If a+ b = 5, sides a,b,c are to be 4, 1, 3 or 3, 2, 3 . Here first triplet is not possible. Similarly the sum a+ b won't be equal to 4, 3, 2, & 1 as the sum of 2 sides should be > third side So, finally the sides of triangle are3, 3, 2 It will be an isosceles triangle with equal sides 3 & base = 2 So perpendicular length from the vertex to the base = √( 3² - 1²) = √8 ( as perpendicular will bisect the base) Area = 1/2 * base * altitude Area = 1/2 * 2 * √8 =√8 =2√2 unit² I di d not understand I di d not understand |
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