diff --git a/Cargo.lock b/Cargo.lock
index 7e69a7f..a91ec56 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "approx"
 version = "0.4.0"
@@ -29,6 +31,14 @@ dependencies = [
  "approx",
 ]
 
+[[package]]
+name = "matrix"
+version = "0.1.0"
+dependencies = [
+ "approx",
+ "structs",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.14"
@@ -51,5 +61,6 @@ version = "0.1.0"
 dependencies = [
  "canvas",
  "color",
+ "matrix",
  "structs",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 808f13e..c96d451 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,3 +10,4 @@ edition = "2018"
 canvas = { path = "canvas" }
 color = { path = "color" }
 structs = { path = "structs" }
+matrix = { path = "matrix" }
diff --git a/src/main.rs b/src/main.rs
index fa4c474..7d4b166 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 use canvas::Canvas;
 use color::Color;
 use structs::Tuple;
+use matrix::Matrix;
 
 use std::fmt;
 use std::fs::File;
@@ -106,4 +107,35 @@ fn main() {
         Err(e) => panic!("did not write. {}", e),
     };
 
+
+    let i = Matrix::identity(4);
+    println!("{:#?}", i);
+    let inverse_i = i.inverse();
+    println!("{:#?}", inverse_i);
+
+
+    let mut a = Matrix::from_array([
+        [1.0, 2.0, 3.0],
+        [4.0, 5.0, 6.0],
+        [7.0, 8.0, 1.0]
+    ]);
+
+    let mut b = a.inverse();
+    println!("{:?}", b);
+    let c = &a * &b;
+    println!("{:?}", c);
+
+    b.transpose();
+    a.transpose();
+    let at = a.inverse();
+    println!("{:?}", b);
+    println!("{:?}", at);
+
+
+    let t = Tuple::point(1.0, 2.0, 3.0);
+    let mut id = Matrix::identity(4);
+    id[1][3] = -3.0;
+    let q = &id * &t;
+    println!("{:?}", id);
+    println!("{:?}", q);
 }