Exploring Midsegments of a Triangle
Students will discover the relationships between a midsegment of a triangle and its third side.https://education.ti.com/en/activity/detail/exploring-midsegments-of-a-triangle
Corresponding Parts of Similar Triangles
Change the scale factor (r) between similar triangles; identify the corresponding parts and establish relationships between them.https://education.ti.com/en/activity/detail/corresponding-parts-of-similar-triangles
Cell Phone Towers
In this activity students explore the locus of a point that is located twice as far from a given point A as it is from given point B. The locus is Apollonius circle. Students discover that the locus is a circle and then prove it. The key property: If a ray bisects an angle of a triangle, then it ...https://education.ti.com/en/activity/detail/cell-phone-towers
Balancing Act
Students will explore the centriod of a triangle. They will discover that it is the center of gravity. They will balance a cardboard triangle on the end of a pencil. Then they will construct the medians with folds and pencil. After students have seen that the center of gravity is the point ...https://education.ti.com/en/activity/detail/balancing-act
Balancing Point
In this activity, students will explore the median and the centroid of a triangle. Students will discover that the medians of a triangle are concurrent. The point of concurrency is the centroid. Students should discover that the center of mass and the centroid are the same for a triangle.https://education.ti.com/en/activity/detail/balancing-point
Circle Geometry: Property of the Segments of Two Chords Intersecting within a Circle
Students will be able to discover the property of two chords segments intersecting within a circle. They will discover the rule about the segments geometrically, numerically, and graphically. Lesson will touch on line of best fit to explore the relationship between the segments of the two chords.https://education.ti.com/en/activity/detail/circle-geometry-property-of-the-segments-of-two-chords-intersecting-within-a-circle
Constructing a Pentagon, An Alternative Method
Use the TN-Nspire (OS 2.0) to construct a regular pentagon using lines, rays, line segments, and circles of various diameters. The characteristics of a regular pentagon are discussed and used to verify the construction meets the criteria of all sides being equal, and all angles being equal. The ...https://education.ti.com/en/activity/detail/constructing-a-pentagon-an-alternative-method
Angle-Side-Side Exploration
Does knowing two sides and a non-included angle of a triangle guarantee it is a unique triangle? This activity will allow students to discover the answer by moving a point on a triangle to determine if another triangle given the same sides and non-included angle is possible.https://education.ti.com/en/activity/detail/anglesideside-exploration
Congruent Triangles
This activity is intended to provide students with an opportunity to discover three methods of proving triangles congruent: SSS, SAS, and ASA.https://education.ti.com/en/activity/detail/congruent-triangles_2
Exponential Functions and the Natural Logarithm
Discover a surprising property involving the relative growth rate of an exponential function.https://education.ti.com/en/activity/detail/exponential-functions-and-the-natural-logarithm
Circles - Angles and Arcs
In this activity, students will investigate inscribed angles, central angles and intercepted arcs relationships in circles.https://education.ti.com/en/activity/detail/circles--angles-and-arcs
Arcs and Central Angles of Circles
Students discover the central angles of circles plus minor and major arcs.https://education.ti.com/en/activity/detail/arcs-and-central-angles-of-circles
Approximating Pi -- Archimedes method
Students will be assigned different regular polygons to construct. They will then construct a circumscribed circle, measure diameter, circumference and perimeter. The measurements will be placed into a spreadsheet and the ratios of circumference/diameter and perimeter/diameter will be calculated.https://education.ti.com/en/activity/detail/approximating-pi--archimedes-method
Minimizing Surface Area of a Cylinder Given a Fixed Volume
Students will discover the relationship between radius and height of a cylinder so that surface area of a cylinder can be minimized while maintaining a fixed volume. This is just an introduction to a project that they will begin after this investigation. Once this is completed, they will redesig...https://education.ti.com/en/activity/detail/minimizing-surface-area-of-a-cylinder-given-a-fixed-volume
Addition of Parts
This activity is a self-contained discussion of the topic of segment and angle addition and allows the teacher to focus on the flow of the class rather than explanation. Students will be able to work through this activity easily and reach usable conclusions on their own. Also, examples are prov...https://education.ti.com/en/activity/detail/addition-of-parts
Maximizing a Paper Cone's Volume
The net for a conical paper cup is formed by cutting a sector from a circular piece of paper. What sector angle creates a net that maximizes the cone's volume? In this activity students will build concrete models, measure the dimensions and calculate the volume. Next, students will use a const...https://education.ti.com/en/activity/detail/maximizing-a-paper-cones-volume
Angle and Perpendicular Bisectors in a Triangle
The students will examine where the perpendicular bisectors and angle bisectors of a triangle intersect. The students will circumscribe a circle around the triangle and will inscribe a circle within the triangle. There is a page at the end of each activity with the circle constructed if the s...https://education.ti.com/en/activity/detail/angle-and-perpendicular-bisectors-in-a-triangle
Nested Similar Triangles
Discover the conditions that make triangles similar by moving the sides opposite the common angle in nested triangles.https://education.ti.com/en/activity/detail/nested-similar-triangles
Triangle Sides & Angles
Students will explore side and angle relationships in a triangle. First, students will discover where the longest (and shortest) side is located relative to the largest (and smallest) angle. Then, students will explore the Isosceles Triangle Theorem and its converse. Finally, students will determ...https://education.ti.com/en/activity/detail/triangle-sides--angles
Scale Factor Area Perimeter
Explore the relationship of perimeter and area in similar triangles when the scale factor is changed.https://education.ti.com/en/activity/detail/scale-factor-area-perimeter
The Ladder Problem Revisited
In this activity students explore the locus of mid-point of the hypotenuse of a fixed length geometrically and algebraically and discover that the median a right triangle is equal to half the length of the hypotenuse. Students then prove this property. The problem: A ladder leans upright against ...https://education.ti.com/en/activity/detail/the-ladder-problem-revisited
The Lunes of Hippocrates
In this activity the students discover a property of this historical figure.https://education.ti.com/en/activity/detail/the-lunes-of-hippocrates
The Pirate Problem
...the palm tree in the treasure map disappears? What begins with inductive reasoning ends with a formal proof. This lesson, easily adapted to middle school, utilizes knowledge of quadrilaterals, congruent triangles, reflection, and symmetry. This high school version requires a healthy dose of a...https://education.ti.com/en/activity/detail/the-pirate-problem
The Pythagorean Theorem—and More
Students construct a triangle and find all angle and side measures. They practice dragging the vertices to form certain types of triangles, and then they confirm the Pythagorean Theorem for right triangles. Moreover, they discover the types of triangle that occur when c2 a2 + b2 or when c2 > a2 +...https://education.ti.com/en/activity/detail/the-pythagorean-theoremand-more
Taxicab Geometry
In this activity, students begin a study of taxicab geometry by discovering the taxicab distance formula. They then use the definition of radius to draw a taxicab circle and make comparisons between a circle in Euclidean geometry and a circle in taxicab geometry. Lastly, they construct taxicab pe...https://education.ti.com/en/activity/detail/taxicab-geometry