Given a right angle triangle:
As shown on the acute angles is 21
So,
[tex]\begin{gathered} \cos \text{ 21=}\frac{adjacent}{\text{hypotenuse}}=\frac{6.4}{H} \\ \\ H=\frac{6.4}{\cos 21}=6.855 \end{gathered}[/tex]
And:
[tex]\begin{gathered} \tan 21=\frac{opposite}{\text{adjacent}}=\frac{y}{6.4} \\ \\ y=6.4\cdot\tan 21=2.457 \end{gathered}[/tex]
the third angle of the triangle =
[tex]90-21=69[/tex]
