Given:
In ΔABC, AB = 5 unit, BC = 2 unit and ∠C = 90°
To find the The value of ∠B.
Formula
By Trigonometric Ratio we know,
[tex]cos \ \theta=\frac{adj}{hyp}[/tex]
Let us take ∠B = θ
With respect to θ, BC is the adjacent side and AB is the hypotenuse.
So,
[tex]cos \ \theta=\frac{BC}{AB}[/tex]
[tex]cos \ B=\frac{2}{5}[/tex]
[tex]B=cos^{-1} (\frac{2}{5} )[/tex]
[tex]B = 66.42^{\circ}[/tex]
Hence, the value of ∠B is 66.42°.
