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The perimeter of a right triangle is 48 cm and the hypotensue is 18 cm. Find its area |
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Answer» Answer: The perimeter of a right angled TRIANGLE is 48 cm , and its area is 96 cm² . Length of its hypotenuse is 20 cm . What is the length of the perpendicular sides ? Solution : Let , In a right angled triangle , B ⇔ BASE P ⇔ Perpendicular H ⇔ Hypotenuse Perimeter of a right angled triangle is sum of all its sides , ➳ PER. = B + P + H Hypotenuse , H = 20 cm ➳ Per. = B + P + 20 But it is given Per. = 48 cm , so , ➳ 48 = B + P + 20 ➳ B + P = 28 ➳ P = 28 - B ... (1) Area of a right triangle is , \to \sf A=\dfrac{1}{2}\times b\times h→A= 2 1
×b×h where , h denotes height = perpendicular (P) b denotes base = Base (B) ➠ A = ¹/₂ × B × P Given , Area of the triangle is 96 cm² ➠ 96 = ¹/₂ × B × P ➠ BP = 192 Sub. (1) , ➠ B ( 28 - B ) = 192 ➠ 28B - B² = 192 ➠ B² - 28B + 192 = 0 ➠ B² - 12B - 16B + 192 = 0 ➠ B ( B - 12 ) - 16 ( B - 12 ) = 0 ➠ ( B - 12 ) ( B - 16 ) = 0 ➠ B = 12 ; 16 cm Sub. B VALUE in (1) , ➠ P = 28 - (12) or 28 - (16) ➠ P = 16 or 12 ➠ P = 16 ; 12 cm So , Base of the triangle = 12 or 16 cm \green{\bigstar}★ Perpendicular of the triangle = 16 or 12 cm \pink{\bigstar}★ Length of the perpendicular sides are 12 and 16 cm respectively |
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