17 lines
589 B
Python
17 lines
589 B
Python
def triangle_area(a, b, c):
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'''
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Given the lengths of the three sides of a triangle. Return the area of
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the triangle rounded to 2 decimal points if the three sides form a valid triangle.
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Otherwise return -1
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Three sides make a valid triangle when the sum of any two sides is greater
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than the third side.
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Example:
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triangle_area(3, 4, 5) == 6.00
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triangle_area(1, 2, 10) == -1
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'''
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if a + b <= c or a + c <= b or b + c <= a:
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return -1
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s = (a + b + c) / 2
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area = (s * (s - a) * (s - b) * (s - c)) ** 0.5
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return round(area, 2) |