P is a point inside the square ABCD. The distances from point P to vertex a, B and C are 1, 2 and 3 respectively. Find the side length of the square Using trigonometric function solution, there are two results under the solution. Why should 5-2 √ 2 be omitted?

P is a point inside the square ABCD. The distances from point P to vertex a, B and C are 1, 2 and 3 respectively. Find the side length of the square Using trigonometric function solution, there are two results under the solution. Why should 5-2 √ 2 be omitted?

If △ PBQ is connected with PQ, it is easy to prove that △ PBQ is an isosceles right triangle, PQ = 2 radical. 2 according to the inverse theorem of Pythagorean theorem, it is obtained that ∠ PQC = 90 °. ∧ APB = ∠ BQC = 135 ° crossing point a and making am ⊥ BP intersecting long line at point m, then △ APM is an isosceles right triangle