
David B. answered 09/04/21
Former Math Teacher and Experienced and Patient Tutor
We have an isosceles right triangle PQR with the right angle at Q and QR = PQ = 10 meters.
For your information side r or PQ is the side opposite angle R and side p or QR is the side opposite angle P
All 3 angles of a triangle have a sum of 180 degrees. Since both angle P and angle R are equal (definition of an isosceles triangle) and therefore 45 degrees each since their sum must be 90 degrees.
This means that QR (opposite side of angle P) = QR (adjacent side of angle P).
The tan of angle P is the ratio of the side opposite angle P over the side adjacent to angle P.
Both of these sides are 10 meters.
So, tan of angle P = 10/10 or 1