This 45-minute test has 9 questions worth 20 points. It covers translations, reflections, rotations, rigid and non-rigid maps, symmetry, and sequences of transformations on the coordinate plane. Show your work.
- Grade: Geometry
- Chapter: Rigid Transformations
- Common Core: G-CO.A.2, G-CO.A.3, G-CO.A.4, G-CO.A.5
- Time: 45 minutes
- Total: 20 points (Question 1: 2 pts; Question 2: 2 pts; Question 3: 2 pts; Question 4: 3 pts; Question 5: 2 pts; Question 6: 2 pts; Question 7: 3 pts; Question 8: 2 pts; Question 9: 2 pts)
Question 1: Translate a triangle (2 points)
Translate triangle \(ABC\) by \(\langle -4,\,3\rangle\). Write the coordinates of the three image vertices.
Question 2: Reflect over y = x (2 points)
Reflect triangle \(JKL\) over the line \(y=x\). Write the coordinates of the image vertices.
Question 3: Rotate clockwise (2 points)
Rotate each point \(90^{\circ}\) clockwise about the origin.
- \((3,\,2)\)
- \((-4,\,5)\)
- \((0,\,-6)\)
Question 4: Sequence of transformations (3 points)
Triangle \(DEF\) has vertices \(D(1,\,2)\), \(E(4,\,2)\), \(F(1,\,6)\). It is reflected over the y-axis and then translated by \(\langle 2,\,-3\rangle\).
- Find the coordinates of the final image. (2 points)
- Show that side \(DE\) has the same length as its final image. (1 point)
Question 5: Identify the transformation (2 points)
Triangle \(ABC\) is mapped onto triangle \(A^{\prime}B^{\prime}C^{\prime}\). Name the transformation and describe it completely.
Question 6: Rigid or not rigid (2 points)
The rule \((x,\,y)\) to \((x,\,3y)\) is applied to segment \(AB\) with \(A(1,\,1)\) and \(B(1,\,4)\).
- Find the length of \(AB\) and the length of its image. (1 point)
- Is the rule a rigid transformation? Explain. (1 point)
Question 7: Symmetry (3 points)
A regular octagon is shown.
- How many lines of symmetry does it have? (1 point)
- What is the smallest positive rotation about its center that maps it onto itself? (1 point)
- How many lines of symmetry does a rectangle that is not a square have? (1 point)
Question 8: Describe a sequence (2 points)
Rectangle \(ABCD\) is mapped onto rectangle \(A^{\prime}B^{\prime}C^{\prime}D^{\prime}\) by a sequence of two rigid transformations. Describe one such sequence.
Question 9: Robot position (2 points)
Diego programs a robot that starts at \((-3,\,4)\) on a grid. It reflects over the x-axis and then moves by the vector \(\langle 5,\,2\rangle\). Where does it end?
See every chapter on the Geometry math page.



