SOLUTION: rod of 20 m length has an isosceles triangular base, where the equal sides are 12 cm each.of the included angle in the base is 40°,calculate: a)thearea of the cross-section. b)T

Algebra ->  Surface-area -> SOLUTION: rod of 20 m length has an isosceles triangular base, where the equal sides are 12 cm each.of the included angle in the base is 40°,calculate: a)thearea of the cross-section. b)T      Log On


   



Question 1086357: rod of 20 m length has an isosceles triangular base, where the equal sides are 12 cm each.of the included angle in the base is 40°,calculate:
a)thearea of the cross-section.
b)The volume of the mental rod.
c)the mass of the mental rod,if it is made of copper ,whose density is 9000kg/m3

Found 2 solutions by addingup, Fombitz:
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
so we have a side-angle-side triangle, or SAS. To find the area:
Area = (ab(sinC))/2 = (12 x 12 x sin(40))/2 = (144 x 0.6428)/2 = 46.28

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
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A=%281%2F2%29Bh
and
B%2F2=12cos%2840%29
B%2F2=9.19
B=18.385cm
and
h%5E2%2B%289.1925%29%5E2=12%5E2
h%5E2=59.4973
h=7.71
So then,
A=%281%2F2%29%287.71%29%2818.385%29
A=70.9cm%5E2
Convert the area to m%5E2,
A=70.9%2F%28100%5E2%29
A=.00709m%5E2
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V=A%2AL
V=0.00709%2A20
V=0.1418m%5E3
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m=rho%2AV
m=9000%2A0.1418
m=1276kg