Question

%20to%20the%20nearest%2010th%2C%20what%20is%20b" id="TexFormula1" title="in triangle ABC, AB=7, BC=10, and the measure of angle B=80, to the nearest 10th, what is b" alt="in triangle ABC, AB=7, BC=10, and the measure of angle B=80, to the nearest 10th, what is b" align="absmiddle" class="latex-formula">

Answer 1

Answer:

b = 11.0

Step-by-step explanation:

From the given properties of the triangle,

b = AC

Applying the cosine rule, we have;

$b^{2}$ = $a^{2}$ + $c^{2}$ - 2acCos B

   = $10^{2}$ + $7^{2}$ - 2(10 x 7) Cos 80

   = 100 + 49 - 140 x 0.17365

   = 149 - 24.311

   = 124.689

b = $\sqrt{124.689}$

  = 11.1664

b = 11.0