 # Draw a triangle with a centroid using OpenCV

Given the three vertices of a triangle, write a Python program to find the centroid of a triangle, and then draw a triangle with its centroid in a black window using OpenCV.

Examples:

`  Input:  (100, 200) (50, 50) (300, 100)  Output:  (150, 116) `

Required Libraries:

` OpenCV Numpy `

Fit:
Create a black window with three color channels at 400x 300. Draw three lines that go through the specified points using the built-in OpenCV lines feature. This will create a triangle on the black window. Find the center of gravity of a triangle using the following simple formula. Draw this centroid on a black window using the circle OpenCV with zero thickness.

Below is the implementation of the above approach:

 ` # Python3 code to draw triangle and search centroid `   ` # importing libraries ` ` import ` ` numpy as np ` ` import ` ` cv2 `   ` # Width and height of the black window ` ` width ` ` = ` ` 400 ` ` height ` ` = ` ` 300 ````   # Create a 400 x 300 black window img = np.zeros ((height, width, 3 ), np.uint8)   # Three vertices (tuples) of a triangle p1 = ( 100 , 200 ) p2 = ( 50 , 50 ) p3 = ( 300 , 100 )   # Draw a triangle using lines # in black window with dots # cv2.line is a built-in function in the opencv library cv2.line (img, p1, p2, ( 255 , 0 , 0 ), 3 ) cv2.line (img, p2, p3, ( 255 ,   0 , 0 ), 3 ) cv2.line (img, p1, p3, ( 255 , 0 , 0 ), 3 )   # centroid search by following formula # (X, Y) = (x1 + x2 + x3 // 3, y1 + y2 + y3 // 3) centroid = ((p1 [ 0 ] + p2 [ 0 ] + p3 [< / code> 0 ]) / / 3 , (p1 [ 1 ] + p2 [ 1 ] + p3 [ 1 ]) / / 3 )    # Draw a centroid on a window cv2.circle (img, centroid, 4 , ( 0 , 255 , 0 )) < p>   # image - window title cv2.imshow ( "image" , img) cv2.waitKey ( 0 ) ```

Exit:

` (150, 116) `