code: def test_triangle(self):
      tri = LinearRing([(0, 0), (2, 5), (7, 0)])
      assert signed_area(tri) == pytest.approx(-7 * 5 / 2)
  
file_path: shapely/shapely/tests/legacy/test_cga.py
imports: import unittest
  import pytest
  from shapely.geometry.polygon import LinearRing, orient, Polygon, signed_area
label_desc: Use image node_id 1 for calling the SignedAreaTestCase obj's underlying member method code with example usage: obj.test_triangle() without return types