public override bool CanAreaBeComputed(Area_Based_Analyses.KnownMeasurementsAggregator known)
{
// Central Angle
if (known.GetAngleMeasure(this.theArc.GetCentralAngle()) < 0) return false;
// Radius / Circle
return theArc.theCircle.CanAreaBeComputed(known);
}
//
// Given known values, can the third side be determined: isosceles right triangle (with base known)
//
public List<KeyValuePair<Segment, double>> CalculateBaseOfIsosceles(Area_Based_Analyses.KnownMeasurementsAggregator known)
{
List<KeyValuePair<Segment, double>> pairs = new List<KeyValuePair<Segment, double>>();
if (!this.provenIsosceles || !(this is IsoscelesTriangle)) return pairs;
//
// Make an isosceles triangle to acquire segments.
//
IsoscelesTriangle isoTri = new IsoscelesTriangle(this);
Segment baseSeg = isoTri.baseSegment;
double baseVal = known.GetSegmentLength(baseSeg);
if (baseVal > 0) return pairs;
//
// Get the other sides.
//
Segment otherSide1, otherSide2;
isoTri.GetOtherSides(baseSeg, out otherSide1, out otherSide2);
// If we know 1 we should know the other, check anyway
double otherVal1 = known.GetSegmentLength(otherSide1);
double otherVal2 = known.GetSegmentLength(otherSide2);
if (otherVal1 < 0 && otherVal2 < 0) return pairs;
//
// Get the base angle.
//
double baseAngleVal = known.GetAngleMeasure(isoTri.baseAngleOppositeLeg1);
if (baseAngleVal < 0) baseAngleVal = known.GetAngleMeasure(isoTri.baseAngleOppositeLeg2);
if (baseAngleVal < 0) return pairs;
//
// Compute the value of the base
//
double baseSideVal = 2.0 * otherVal1 * Math.Cos(Angle.toRadians(baseAngleVal));
pairs.Add(new KeyValuePair<Segment, double>(baseSeg, baseSideVal));
return pairs;
}
// Does the included Trig Formula apply?
private double TrigArea(Area_Based_Analyses.KnownMeasurementsAggregator known)
{
for (int s = 0; s < orderedSides.Count; s++)
{
double a = known.GetSegmentLength(orderedSides[s]);
double b = known.GetSegmentLength(orderedSides[(s+1) % orderedSides.Count]);
double theta = known.GetAngleMeasure(new Angle(orderedSides[s], orderedSides[(s+1) % orderedSides.Count]));
if (a > 0 && b > 0 && theta > 0)
{
return TrigArea(a, b, theta);
}
}
return -1;
}
public List<KeyValuePair<Segment, double>> RightTriangleTrigApplies(Area_Based_Analyses.KnownMeasurementsAggregator known)
{
List<KeyValuePair<Segment, double>> pairs = new List<KeyValuePair<Segment, double>>();
if (!(this is RightTriangle) && !this.provenRight) return pairs;
//
// Make a right
//
RightTriangle rightTri = new RightTriangle(this);
Angle otherAngle1, otherAngle2;
Angle rightAngle = rightTri.rightAngle;
rightTri.GetOtherAngles(rightAngle, out otherAngle1, out otherAngle2);
double angleMeasure1 = known.GetAngleMeasure(otherAngle1);
double angleMeasure2 = known.GetAngleMeasure(otherAngle2);
// Need to know one side length
if (angleMeasure1 < 0 && angleMeasure2 < 0) return pairs;
double knownSegVal = -1;
Segment knownSeg = null;
foreach (Segment side in orderedSides)
{
knownSegVal = known.GetSegmentLength(side);
if (knownSegVal > 0)
{
knownSeg = side;
break;
}
}
// Need to know one side length
if (knownSegVal < 0) return pairs;
// Need at least one measure.
if (angleMeasure1 > 0) return CalcSides(rightTri, rightAngle, otherAngle1, angleMeasure1, knownSeg, knownSegVal);
if (angleMeasure2 > 0) return CalcSides(rightTri, rightAngle, otherAngle2, angleMeasure2, knownSeg, knownSegVal);
return pairs;
}
public override double GetArea(Area_Based_Analyses.KnownMeasurementsAggregator known)
{
if (theArc is Semicircle) return (theArc as Semicircle).GetArea(known);
// Central Angle; this is minor arc measure by default
double angleMeasure = Angle.toRadians(known.GetAngleMeasure(this.theArc.GetCentralAngle()));
if (angleMeasure <= 0) return -1;
// Make a major arc measure, if needed.
if (theArc is MajorArc) angleMeasure = 2 * Math.PI - angleMeasure;
// Radius / Circle
double circArea = theArc.theCircle.GetArea(known);
if (circArea <= 0) return -1;
// The area is a proportion of the circle defined by the angle.
return (angleMeasure / (2 * Math.PI)) * circArea;
}