a right-angled is such that the two shorter sides are (2x+1)centimetre and (5x-3) centimetre.If the area of the triangle is 42 centimetre^2,find the lengths of the two sides
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a right-atngled is such that the two shorter sides are (2x+1)centimetre and (5x-3) centimetre.If the area of the triangle is 42 centimetre^2,find the lengths of the two sides
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2 answers
Assuming you are talking about a right-angled triangle ...
area = (1/2) base x height
42 = (1/2)(2x+1)(5x-3)
84 = 10x^2 - x - 3
10x^2 - x - 87 = 0
(x - 3)(10x + 29) = 0
x = 3 or x = -19, but x = -29 would give us negative sides, so ...
x = 3 gives us sides of 7 and 12
check: (1/2)(7)(12) = 42 , looks good
area = (1/2) base x height
42 = (1/2)(2x+1)(5x-3)
84 = 10x^2 - x - 3
10x^2 - x - 87 = 0
(x - 3)(10x + 29) = 0
x = 3 or x = -19, but x = -29 would give us negative sides, so ...
x = 3 gives us sides of 7 and 12
check: (1/2)(7)(12) = 42 , looks good
1 answer