Question

Find the missing side or angle.

Round to the nearest tenth.
B=45°
a=9
c=19
b=[ ]

Answer 1

`14.1`

Explanation:

Since we have two sides of a triangle and the angle between them, we can use the Law of Cosines.

For any triangle, the Law of Cosines states:

`b^2=a^2+c^2-2ac\cos B`, where
`a`,
`b`, and
`c` are all interchangeable.

Substituting given values, we have:

`b^2=9^2+19^2-2(9)(19)\cos 45^(\circ),\\b^2=200.169480834,\\b\approx \boxed{14.1}`