code: def rotated_form(a_, b_, angles):
      cos_a = paddle.cos(angles)
      sin_a = paddle.sin(angles)
      a = a_ * paddle.pow(cos_a, 2) + b_ * paddle.pow(sin_a, 2)
      b = a_ * paddle.pow(sin_a, 2) + b_ * paddle.pow(cos_a, 2)
      c = (a_ - b_) * cos_a * sin_a
      return a, b, c
  
file_path: PaddleDetection/ppdet/modeling/losses/probiou_loss.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import paddle
  import paddle.nn.functional
  from ppdet.core.workspace import register, serializable
label_desc: Use image node_id 2 for calling a global function with example usage: rotated_form(a_, b_, angles) and returns: a,  b,  c