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britbrat4290
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Solve the triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. a = 7, b = 7, c = 5
 one year ago
 one year ago
britbrat4290 Group Title
Solve the triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. a = 7, b = 7, c = 5
 one year ago
 one year ago

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britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
B. A = 69°, B = 69°, C = 42°??
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
wrong
 one year ago

mebs Group TitleBest ResponseYou've already chosen the best response.0
Try Using cosine law
 one year ago

mebs Group TitleBest ResponseYou've already chosen the best response.0
\[7^{2} = 7^{2} + 5^{2}  2(7)(5)cosA\]
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
my answers need to be in degrees
 one year ago

mebs Group TitleBest ResponseYou've already chosen the best response.0
you get \[cosA = \frac{ 25 }{ 70 }\] than do arc cosine. you get angle 69.07
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
i need degrees for a b n c ??
 one year ago

mebs Group TitleBest ResponseYou've already chosen the best response.0
you get angles 41.8 and 69.07. again
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
A. A = 70°, B = 70°, C = 40° B. A = 69°, B = 69°, C = 42° C. A = 42°, B = 69°, C = 69° D. A = 69°, B = 42°, C = 69°
 one year ago

mebs Group TitleBest ResponseYou've already chosen the best response.0
dw:1375984676609:dw ?
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
thanks
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
deff not 69 deg
 one year ago

genius12 Group TitleBest ResponseYou've already chosen the best response.1
Note that the triangle is isosceles:dw:1375984026354:dw
 one year ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
ok ? still confused
 one year ago

genius12 Group TitleBest ResponseYou've already chosen the best response.1
Now use the cosine law:\[\bf a^2=b^2+c^22bc \cos(A) \implies 5^2=7^2+7^22(7)(7)\cos(A)\]Note that 'A' is the angle opposite side BC. Now rearrange and solve for cos(A):\[\bf \implies \cos(A)=\frac{73}{98}=0.7445 \implies \cos^{1}(0.7445)=A=41.884 \ degrees\]
 one year ago

genius12 Group TitleBest ResponseYou've already chosen the best response.1
Now because the triangle is isosceles, the remaining two angles B and C are equal so we can find each of them by subtracting A from 180 and dividing the result by 2:\[\bf \angle B=\angle C=\frac{ 180 41.884}{ 2 }=69.058 degrees\]Rounding off our results to the nearest degree we get:\[\bf \angle A =42 \ degrees\]\[\bf \angle B=\angle C=69 \ degrees\] @britbrat4290
 one year ago

genius12 Group TitleBest ResponseYou've already chosen the best response.1
@britbrat4290 So your answer is correct =]
 one year ago
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