diff --git a/interfaces/demo3.go b/interfaces/demo3.go
new file mode 100644
index 0000000..c7bcbd6
--- /dev/null
+++ b/interfaces/demo3.go
@@ -0,0 +1,51 @@
+/**
+
+Type Assertion explained demo3.go
+  
+BSD 3-Clause License
+
+Copyright (c) 2024 Mass Collaboration Labs and contributors
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  
+ **/
+
+package interfaces
+
+import "fmt"
+
+func verify(i interface{}) {
+	number, ok := i.(int)
+	fmt.Println(number, ok)
+}
+
+func Demo3() {
+	var number1 interface{} = "Engin"
+	verify(number1)
+
+	var number2 interface{} = 5
+	verify(number2)
+}
diff --git a/main.go b/main.go
index 63514bb..375374a 100644
--- a/main.go
+++ b/main.go
@@ -122,4 +122,5 @@ func main() {
 	defer_statement.Demo3()
 
 	error_handling.Demo1()
+	interfaces.Demo3()
 }