Question

Law of cosines: a2 = b2 + c2 -2bccos(A) What is the value of s to the nearest whole number?

Answer 1

Answer:

14

Step-by-step explanation:

The law of cosines is a² = b²+c²-2bc(cos A).

We will use s in place of a, since it is the unknown side.  This makes b and c 8 and 9.

Angle A will be the angle opposite side a, or in this case side s.  This makes it 111.

This gives us

s² = 8²+9²-2(8)(9)(cos 111)

s² = 64+81-2(8)(9)(cos 111)

s² = 145-144(cos 111)

s² = 196.605

Take the square root of each side:

√(s²) = √(196.605)

s = 14.02 ≈ 14

Answer 2

Answer:

14

Step-by-step explanation: