Question

Find the missing side or angle.

Round to the nearest tenth.
A=78°
b=2
C=4
a=[ ? )

Answer 1

The answer for Acellus people is a=4.1

Explanation:

Answer 2

`a=4.1`

Explanation:

The Law of Cosines is given as:

`a^2=c^2+b^2-2cb\cos A`.

Plugging in given values, we get:

`a^2=4^2+2^2-2\cdot 4 \cdot 2\cos 78^(\circ),\\a^2=16+4-16\cos 78^(\circ),\\a^2\approx √(16.673),\\a\approx \fbox{$4.1$}`.