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4 years ago

Solve the following triangle in which given sides are a=7 b=7 c=9

1 answer:

8 0

We have an isosceles triangle;
A=opposite angle side a.
B=opposite angle side b.
C=opposite angle side c.

A=B
Method 1:

We can divide the isosceles triangle in two right triangles,
hypotenuse=7
side=9/2=4.5

B=A=arccossine (4.5/7)=49.994799...º≈50º
C/2=90º-50º=40º ⇒ C=2*40º=80º

Answer:
a=7; A=50º
b=7; B=50º
<span>c=9; C=80º

Method 2:
Law of cosines:
a²=b²+c²-2bcCosA ⇒CosA=(a²-b²-c²)/(-2bc)
CosA=(49-49-81) / (-126)=0.642857
A=arco cos (81/126)≈50º

B=A=50º

A+B+C=180º
50º+50º+C=180º
C=180º-100º
C=80º

Answer:

</span>a=7; A=50º
b=7; B=50º
<span>c=9; C=80º</span>

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3 years ago

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Step-by-step explanation:

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$\vec s(t)=(1-t)(-1,0)+t(2,-\pi)=(3t-1,-\pi t)$

with $0\le t\le1$ . Then

$\displaystyle\int_C(\sin x\,\mathrm dx+\cos y\,\mathrm dy)$

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