As per the trigonometry rules , in a right angled triangle tan R is given as:
[tex]tan R = \frac{Perpendicular}{Base}[/tex]
Now from the given figure we have
Perpendicular = 20
Base =21
Plugging these values in the formula given above:
[tex]tan R = \frac{20}{21}[/tex]
tan R = 0.95238
Rounding it off , we get
tan R = 0.9524
Answer: option third , 0.9524
