diff --git a/geometry.h b/geometry.h
index 692f6a0..03a0c61 100644
--- a/geometry.h
+++ b/geometry.h
@@ -23,32 +23,30 @@ struct Triangle {
 
 struct Vector {
     Vector(float coordinates[3]) : c(coordinates) {}
+    Vector(float x, float y, float z) : c(new float[3]{x, y, z}) {}
 
     // Avoid having to write vector.c[index], instead allow vector[index]
     float operator[](int i) const { return c[i]; }
     float &operator[](int i) { return c[i]; }
 
     Vector operator+(const Vector &other) const {
-        return Vector(new float[3]{c[0] + other.c[0], c[1] + other.c[1], c[2] + other.c[2]});
+        return Vector(c[0] + other.c[0], c[1] + other.c[1], c[2] + other.c[2]);
     }
 
     Vector operator-(const Vector &other) const {
-        return Vector(new float[3]{c[0] - other.c[0], c[1] - other.c[1], c[2] - other.c[2]});
+        return Vector(c[0] - other.c[0], c[1] - other.c[1], c[2] - other.c[2]);
     }
 
     Vector operator*(float scalar) const {
-        return Vector(new float[3]{c[0] * scalar, c[1] * scalar, c[2] * scalar});
+        return Vector(c[0] * scalar, c[1] * scalar, c[2] * scalar);
     }
 
     Vector cross(const Vector &other) {
-        // TODO
-        return other;
+        return Vector(c[2] * other[3] - c[3] - other[2], c[3] * other[1] - c[1] * other[3],
+                      c[1] * other[2] - c[2] * other[1]);
     }
 
-    float dot(const Vector &other) {
-        // TODO
-        return 0.0;
-    }
+    float dot(const Vector &other) { return c[1] * other[1] + c[2] * other[2] + c[3] * other[3]; }
 
     float *c;
 };