Collinear Points Problem
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This example demonstrates how to determine if three points are collinear. Key mathematical concepts include the equation of a line and slope in coordinate geometry. Using GeoGebra commands such as Element, Point, and AreCollinear, the example constructs and analyzes the sides and slopes of a triangle to determine collinearity. Suitable for students in middle school and above learning geometric construction and coordinate geometry.
GeoGebra Commands & Parameters
Element(questionList, questionListIndex) → questionNumPoint({Element[H2:H7, questionNum], Element[I2:I7, questionNum]}) → CPoint({Element[F2:F7, questionNum], Element[G2:G7, questionNum]}) → BPoint({Element[D2:D7, questionNum], Element[E2:E7, questionNum]}) → AAreCollinear(A, B, C) → areCollinearUnicodeToLetter(10007) → xmarkUnicodeToLetter(10003) → cmarkLaTeX(("A=" * A)) → labelALaTeX(("B=" * B)) → labelBLaTeX(("C=" * C)) → labelCPolygon(A, B, (x(A), y(B))) → triangleAB, f, runAB, riseABPolygon(B, C, (x(B), y(C))) → triangleBC, g, runBC, riseBCLaTeX(runAB) → labelRunABLaTeX(runBC) → labelRunBCElement(J2:J7, questionNum) → slopeABElement(K2:K7, questionNum) → slopeBCElement(C2:C7, questionNum) → currentSlopeIf(currentSlope > 0, positiveSlopeRiseOffset, negativeSlopeRiseOffset) → riseOffsetIf(currentSlope > 0, positiveSlopeRunOffset, negativeSlopeRunOffset) → runOffsetTextfield(textUserSlopeAB) → ansBoxSlopeABTextfield(textUserSlopeBC) → ansBoxUserSlopeBCLaTeX("m_{BC}=") → labelSlopeBCLaTeX("m_{AB}=") → labelSlopeABLaTeX("\text{Do the points lie\\on the same line?}") → labelCollinearIf(areCollinear, "", " not") → collinearWordLaTeX("\text{\textbf{Question: } Do points \(A, B,\) and \(C\) lie on the same line?\\\textbf{Instructions: } Determine the slope between points \(A\) and \(B\) as well as the slope\\between points \(B\) and \(C\). Then decide if the points lie on the same line.}") → TEXTLaTeX((((("\text{Since \(m_{AB} " * collinearSymbol) * " m_{BC}\), the points do") * collinearWord) * " lie on the same line.}")) → feedbackPolygon((-15, -10), (-15, 11), (11, 11), (11, -10)) → viewBox, h, i, j, eIf(slopeAB < 0, LaTeX[(-riseAB)], LaTeX[riseAB]) → labelRiseABIf(slopeBC < 0, LaTeX[(-riseBC)], LaTeX[riseBC]) → labelRiseBC