In the given figure for <R ,the opposite side is r and the adjacent side is s.
Given r=7,s=10.
Tan of any angle is the ratio of opposite and hypotenuse.
Tan R=
![(opposite )/(hypotenuse)](https://img.qammunity.org/2019/formulas/mathematics/high-school/9lbkq3240bco84wxy3wxfiyi94sa6hmkxf.png)
Substituting values of opposite r=7 and adjacent s=10 we have:
Tan R =
![(7)/(10) =0.7](https://img.qammunity.org/2019/formulas/mathematics/high-school/4a2k7fwo1f53knf4667fu1bymuf2asa9ij.png)
![</p><p> R= Tan^(-1) (0.7)](https://img.qammunity.org/2019/formulas/mathematics/high-school/1fyjip4fymrvu9f8gw7ujfic6tkbrmauqn.png)
R= 34.99 degrees
R= 35 degrees
Option A is the right answer.