Sss triangle

Calculate the area and heights in the triangle ABC by sides a = 8cm, b = 11cm, c = 12cm

Result

S =  42.789 cm2
h1 =  10.697 cm
h2 =  7.78 cm
h3 =  7.132 cm

Solution:

a=8 cm b=11 cm c=12 cm  s=(a+b+c)/2=(8+11+12)/2=312=15.5 cm S=s⋅ (s−a)⋅ (s−b)⋅ (s−c)=15.5⋅ (15.5−8)⋅ (15.5−11)⋅ (15.5−12)≐42.7895=42.789 cm2a = 8 \ cm \ \\ b = 11 \ cm \ \\ c = 12 \ cm \ \\ \ \\ s = (a+b+c)/2 = (8+11+12)/2 = \dfrac{ 31 }{ 2 } = 15.5 \ cm \ \\ S = \sqrt{ s \cdot \ (s-a) \cdot \ (s-b) \cdot \ (s-c) } = \sqrt{ 15.5 \cdot \ (15.5-8) \cdot \ (15.5-11) \cdot \ (15.5-12) } \doteq 42.7895 = 42.789 \ cm^2
S=a⋅ h12 h1=2⋅ S/a=2⋅ 42.7895/8≐10.6973=10.697  cm S = \dfrac{ a \cdot \ h_{ 1 } }{ 2 } \ \\ h_{ 1 } = 2 \cdot \ S / a = 2 \cdot \ 42.7895 / 8 \doteq 10.6973 = 10.697 \ \text{ cm }
h2=2⋅ S/b=2⋅ 42.7895/11≐7.7798=7.78  cm h_{ 2 } = 2 \cdot \ S / b = 2 \cdot \ 42.7895 / 11 \doteq 7.7798 = 7.78 \ \text{ cm }
h3=2⋅ S/c=2⋅ 42.7895/12=7.1315=7.132  cm h_{ 3 } = 2 \cdot \ S / c = 2 \cdot \ 42.7895 / 12 = 7.1315 = 7.132 \ \text{ cm }

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