Question

Round to the nearest tenth (picture provided)

Answer 1

Answer:

d. 6.3

Step-by-step explanation:

Given $b=3,c=9$ and $A=21\degree$, we can use the cosine rule to find $a$.

The cosine rule is given by;

$a^2=b^2+c^2-2bc\cos(A)$

We substitute the values to obtain;

$a^2=3^2+9^2-2(3)(9)\cos(21\degree)$

$a^2=9+81-54\cos(21\degree)$

$a^2=90-50.4133$

$a^2=39.5867$

$a=\sqrt{39.5867}$

$a=6.2918$

To the nearest tenth, $a=6.3$