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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
 11 months ago
 11 months 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
 11 months ago
 11 months ago

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

mebs Group TitleBest ResponseYou've already chosen the best response.0
sounds good.
 11 months ago

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
wrong
 11 months ago

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

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

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

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

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

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

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
thanks
 11 months ago

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

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

britbrat4290 Group TitleBest ResponseYou've already chosen the best response.0
ok ? still confused
 11 months 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):\[\bf \implies \cos(A)=\frac{73}{98}=0.7445 \implies \cos^{1}(0.7445)=A=41.884 \ degrees\]
 11 months 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
 11 months ago

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