#1 Using the right triangle below, find the cosine of angle A.

Answer: 0.8
Step-by-step explanation:
Using the Cosine formula :
[tex]Cos A = \frac{b^{2}+c^{2}-a^{2}}{2bc}[/tex]
[tex]a = 6[/tex]
[tex]b = 8[/tex]
[tex]c = 10[/tex]
substituting into the formula , we have
[tex]Cos A = \frac{8^{2}+10^{2}-6^{2}}{2(8)(10)}[/tex]
[tex]Cos A = \frac{64+100-36}{160}[/tex]
[tex]Cos A = \frac{164-36}{160}[/tex]
[tex]Cos A = \frac{128}{160}[/tex]
Therefore :
Cosine of angle A = 0.8