lib: generic read_triangle function

lib/geometry/src/lib.rs

@@ -99,3 +99,17 @@ pub fn read_point(prompt: &str) -> Point {
         y: coords[1],
     }
 }
+
+// Reads the coordinates of the vertices for a triangle
+// and constructs a `triangle` object
+pub fn read_triangle(name: &str) -> Triangle {
+    println!(
+        "Enter the coordinates for the three vertices of triangle {}:",
+        name
+    );
+    let p1 = read_point("First vertex (x y):");
+    let p2 = read_point("Second vertex (x y):");
+    let p3 = read_point("Third vertex (x y):");
+
+    Triangle { p1, p2, p3 }
+}