Question

What is m∠C ? Anyone willing to help me (:

Answer 1

Answer:

50°

Step-by-step explanation:

Use the cosine law:

$AB^2=CB^2+CA^2-(CB)(CA)\cos(\angle C)$

We have:

$AB=6,\ CB=6.5,\ CA=7.5$

Substitute:

$6^2=6.5^2+7.5^2-2(6.5)(7.5)\cos(\angle C)$

$36=42.25+56.25-97.5\cos(\angle C)$

$36=98.5-97.5\cos(\angle C)$           subtract 98.5 from both sides

$-62.5=-97.5\cos(\angle C)$           divide both sides by (-97.5)

$\cos(\angle C)\approx0.641\to m\angle C\approx50^o$