Add Torque = ForcePerLength * Area operator (#754)

Author: lwestfall

UnitsNet.Tests/CustomCode/ForcePerLengthTests.cs

@@ -53,10 +53,17 @@ public void ForceDividedByForcePerLengthEqualsLength()
         }
 
         [Fact]
-        public void ForcePerLenghTimesLengthEqualForce()
+        public void ForcePerLengthTimesLengthEqualForce()
         {
             Force force = ForcePerLength.FromNewtonsPerMeter(10) * Length.FromMeters(9);
             Assert.Equal(force, Force.FromNewtons(90));
         }
+
+        [Fact]
+        public void ForcePerLengthTimesAreaEqualTorque()
+        {
+            Torque torque = ForcePerLength.FromNewtonsPerMeter(10) * Area.FromSquareMeters(9);
+            Assert.Equal(torque, Torque.FromNewtonMeters(90));
+        }
     }
 }

UnitsNet/CustomCode/Quantities/ForcePerLength.extra.cs

@@ -5,7 +5,7 @@ namespace UnitsNet
 {
     public partial struct ForcePerLength
     {
-        /// <summary>Get <see cref="Force"/> from <see cref="ForcePerLength"/> divided by <see cref="Length"/>.</summary>
+        /// <summary>Get <see cref="Force"/> from <see cref="ForcePerLength"/> multiplied by <see cref="Length"/>.</summary>
         public static Force operator *(ForcePerLength forcePerLength, Length length)
         {
             return Force.FromNewtons(forcePerLength.NewtonsPerMeter * length.Meters);
@@ -22,5 +22,11 @@ public partial struct ForcePerLength
         {
             return Pressure.FromNewtonsPerSquareMeter(forcePerLength.NewtonsPerMeter / length.Meters);
         }
+
+        /// <summary>Get <see cref="Torque"/> from <see cref="ForcePerLength"/> multiplied by <see cref="Area"/>.</summary>
+        public static Torque operator *(ForcePerLength forcePerLength, Area area)
+        {
+            return Torque.FromNewtonMeters(forcePerLength.NewtonsPerMeter * area.SquareMeters);
+        }
     }
 }