If b=16°45’ and c=13 then find a (picture provided)

A. 12.4

Step-by-step explanation:

To find a, we'll use the Law of Sines that says:

And we'll isolate a to get:

We first need to find A, which is easy.  The sum of the interior angles of a triangle is 180 degrees... and we already have 2 of them, so:

A = 180 - 90 - 16.75 = 73.25

(converted 16°45' to 16.75)

Then we will plug-in the information we already have

So, let's round it to 12.4 to match the answer A.

The length of side marked a is 12.4 units.

Step-by-step explanation:

In ΔABC

∠B = 16°45’ = 16.75°

1 min arc =

c = 13 units

a = ?

The length of side marked a is 12.4 units.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

the first option is the answer.