In the triangle PQR R= 90 DEGREE RQ 8CM AND RP6.2 CM FIND ANFLE Q

In your right triangle, the side PR is opposite angle Q and the side RQ is adjacent to angle Q.

The function, tan is defined to be:  tan  =  opp / adj.

tan(Q)  =  PR / RQ     --->     tan(Q)  =  6.2 / 8  =  0.775

To solv for angle Q, use invtan:     Q  =  invtan(0.775)  =  65.9 degrees.