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Find a, B, C
b=30
c=15
A=140
a=?
B=?
C=?

User Irm
by
8.4k points

1 Answer

5 votes

Answer:

Explanation:

To find the values of a, B, and C, we can use the Law of Cosines, which relates the lengths of the sides of a triangle to the cosine of one of its angles. Specifically, we can use the formula:

c^2 = a^2 + b^2 - 2ab*cos(C)

where c is the length of the side opposite angle C, and a and b are the lengths of the other two sides.

Substituting the given values, we get:

15^2 = a^2 + 30^2 - 2a30*cos(140)

Simplifying and solving for a, we get:

a^2 = 15^2 + 30^2 - 21530*cos(140)

a^2 = 1275.8476

a ≈ 35.7

So, we have found that a ≈ 35.7. Now, to find the angle B, we can use the Law of Sines, which relates the lengths of the sides of a triangle to the sines of its angles. Specifically, we can use the formula:

sin(B) / b = sin(C) / c

Substituting the given values, we get:

sin(B) / 30 = sin(140) / 15

Simplifying and solving for sin(B), we get:

sin(B) = (30*sin(140)) / 15

sin(B) = 1.982

However, since the sine function is only defined between -1 and 1, we can see that there is no angle B that satisfies this equation. This means that the given values do not form a valid triangle, and there is no solution for angle B.

Therefore, we can conclude that:

a ≈ 35.7

B = no solution

C = 140 degrees

User Jeff Stewart
by
9.0k points