diff --git a/docs/README.md b/docs/README.md
index 63f8727939..a53b84305f 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -3,8 +3,10 @@
 - Circle: S = πR²
 - Rectangle: S = ab
 - Square: S = a²
+- Triangle: S = 0.5 * ah
 
 ## Perimeter
 - Circle: P = 2πR
 - Rectangle: P = 2a + 2b
-- Square: P = 4a
\ No newline at end of file
+- Square: P = 4a
+- Triangle: P = a + b + c