diff --git a/README.md b/README.md
index c309402..750e335 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
 # reasoningaboutspace
 
-we are doing this to try the tests functions about rotation matrix
\ No newline at end of file
+we are doing this to try the tests functions about rotation matrix
+
+create2DRotationMatrix.m takes the rotation angle z, and returns the corresponding rotation matrix
\ No newline at end of file
diff --git a/create2DRotationMatrix.m b/create2DRotationMatrix.m
new file mode 100644
index 0000000..e11c6fd
--- /dev/null
+++ b/create2DRotationMatrix.m
@@ -0,0 +1,54 @@
+## Copyright (C) 2023 gabri
+##
+## This program is free software: you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {} {@var{retval} =} create2DRotationMatrix (@var{input1}, @var{input2})
+##
+## @seealso{}
+## @end deftypefn
+
+## Author: gabri <gabri@DESKTOP-AA36H6D>
+## Created: 2023-02-03
+
+function myrotationmatrix = create2DRotationMatrix (z)
+  %%%%%%%%%%%%%%%%%
+  %the function create2DRotationMatrix takes an agle in degrees as a argument,
+  %and returns the corresponding 2D rotation matrix
+  %
+  %
+  %     INPUT : rotation angle in degrees
+  %
+  %     OUTPUT : rotation matrix in size 2 by 2
+  %
+  %Created by: Gabriel LUCAS
+  %Date Creation: 03/02/2023 11:05:22
+  %
+  %Last Modified: 03/02/2023 11:06:51
+  %%%%%%%%%%%%%%%%%%
+  z = z*(pi/180);
+  myrotationmatrix = [cos(z),sin(z);(-sin(z)),cos(z)]
+  
+  %test
+  angle = 90;
+  expectedrotationmatrix = [0 1;-1 0];
+  angle = angle*(pi/180);
+  testrotationmatrix = [cos(angle),sin(angle);(-sin(angle)),cos(angle)]
+  if (abs(abs(expectedrotationmatrix .- testrotationmatrix)) < 1e-10)
+    disp("Test #1 Passed")
+  else
+    disp("Test #1 Failed")
+  endif
+  
+endfunction