Take a point p outside a right triangle ABC and rotate it 180 degrees counter clockwise. How to draw?

Take a point p outside a right triangle ABC and rotate it 180 degrees counter clockwise. How to draw?

Connect PA, Pb, PC respectively and extend to D, e, f respectively, so that PD = PA, PE = Pb, PF = PC;
Then connect the def in sequence, then △ DEF is

First draw a triangle arbitrarily, then draw a vertex of the triangle respectively, and rotate the figure by the following degrees counterclockwise: (1) 30 degrees
（2）60°（3）90°（4）180°

No matter how you rotate it, it's not a triangle

Exploration and research: (method 1) Figure 4 (1) is the result of right triangle ABC rotating 90 ° counterclockwise around its acute vertex a, so ∠ ba
E = 90 ° and the quadrilateral acfd is a square, its area is equal to the area of quadrilateral affe, and the area of quadrilateral abef is equal to the sum of the areas of RT △ BAE and RT △ BFE. According to figure 4 (1), write the process of verifying Pythagorean theorem

(method 1) s Square acfd = s △ BAE + s △ BFE, namely: 2B2 = C2 + (B + a) (B-A) ∧ A2 + B2 = C2

Draw a triangle AOB around the point O counterclockwise rotation 90 graphics

Draw the figure of triangle AOB rotating 90 counterclockwise around point o