Secrets in the Triangle
Students will use the geometry screens of the TI-Nspire™ to find points of concurrency by constructing the altitudes, perpendicular bisectors, and medians in triangles. The Euler Line will be found and extensions given.https://education.ti.com/en/activity/detail/secrets-in-the-triangle
The sum of the interior angles of regular polygons
The students will construct triangles within regular-sided polygons to determine the sum of the interior angles. They will then, using statistics, create a linear regression to determine the relationship between the number of sides of a regular polygon and the sum of its interior angles.https://education.ti.com/en/activity/detail/the-sum-of-the-interior-angles-of-regular-polygons
Similar Figures - Using Ratios to Discover Properties
Students will explore similar triangles and set up ratios to discover properties of similar triangles.https://education.ti.com/en/activity/detail/similar-figures--using-ratios-to-discover-properties
Triangle Midsegment Exploration
The activity has the students investigate the relationship of the midsegment to the third side of the triangle. In addition the students investigate the area of the smaller triangles compared to the larger one and uses the results to solve the "campground" problem. There is a set of follow-up q...https://education.ti.com/en/activity/detail/triangle-midsegment-exploration
Paths of Rectangles
This exploration for preservice teachers, looks at how the lengths of the sides of rectangles with equal areas are related. The rectangles are constructed so that one vertex is at the origin. The path of the opposite vertex is an example of indirect variation and demonstrates a connection between...https://education.ti.com/en/activity/detail/paths-of-rectangles
The Tale of Two Tangents
This activity allows students to investigate the relationship between the angle formed by two tangents to a circle and the arcs they intercept.https://education.ti.com/en/activity/detail/the-tale-of-two-tangents
Properties of Parallelograms
Students will manipulate parallelograms to discover the relationships between the sides, angles, and diagonals of parallelograms.https://education.ti.com/en/activity/detail/properties-of-parallelograms_7
Discovering the Triangle Inequality Theorem with the TI-Nspire
Students progress through a series of investigations regarding the lengths of the sides of a triangle. This activity, for discovering the Triangle Inequality Theorem, can be used as either a teacher demonstration or as a classroom activity.https://education.ti.com/en/activity/detail/discovering-the-triangle-inequality-theorem-with-the-tinspire
Properties of Trapezoids and Kites
Students investigate the properties of trapezoids, isosceles trapezoids, and kites by measuring sides and angles in the figures and by constructing and measuring the diagonals of the figures. By dragging vertices of each figure, they can make and test conjectures by seeing which properties hold t...https://education.ti.com/en/activity/detail/properties-of-trapezoids-and-kites
Points of Concurrency in Triangles
In this activity, students will use their Nspire handhelds to discover the different points of concurrencies in triangles. The students will take advantage of the dynamic capabilities to discover the circumcenter, incenter, and centroid of triangles.https://education.ti.com/en/activity/detail/points-of-concurrency-in-triangles
Proof by Counterexample of the SSA and AAA Cases
Students will use the geometry functions of the Nspire to create triangles with SSA and AAA details. Then these counterexamples are used to disprove possible SSA and AAA conjectures.https://education.ti.com/en/activity/detail/proof-by-counterexample-of-the-ssa-and-aaa-cases
Area of a Triangle Between Parallel Lines
This is an investigation of what happens to the area of a triangle when one vertex moves along a line parallel to the side opposite the vertex.https://education.ti.com/en/activity/detail/area-of-a-triangle-between-parallel-lines
Applications of Similar Figures
Students will identify corresponding parts of figures and use the definition of similar figures to solve real-world applications involving rectangles and triangles.https://education.ti.com/en/activity/detail/applications-of-similar-figures
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
Congruent Triangles - Conditions that Prove Congruency
Students will investigate what conditions are necessary to prove two triangles are congruent.https://education.ti.com/en/activity/detail/congruent-triangles--conditions-that-prove-congruency
Angles & Chords in a Circle
This activity is designed to allow students to gain an understanding of the relationship between the arcs and angles formed by intersecting chords in a circle. It includes an interactive geometry page, some circle problems, and a Euclidean proof.https://education.ti.com/en/activity/detail/angles--chords-in-a-circle
The Geometric Mean
In this activity, students will establish that several triangles are similar and then determine that the altitude to the hypotenuse of a right triangle is the geometric mean between the segments into which it divides the hypotenuse.https://education.ti.com/en/activity/detail/the-geometric-mean_1
The Magic of Central Angles
This activity allows students to investigate the relationship between central angles and the arcs they intercept.https://education.ti.com/en/activity/detail/the-magic-of-central-angles
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
Secants and Angles in a Circle
This activity is designed to allow students to gain an understanding of the relationship between the arcs and angles formed by secants drawn from a common external point outside a circle. It includes an interactive geometry page, some circle problems, and a Euclidean proof.https://education.ti.com/en/activity/detail/secants-and-angles-in-a-circle
Remote Interior Angles
Students use the handheld activity and questions to explore remote interior angles.https://education.ti.com/en/activity/detail/remote-interior-angles
Investigation of Similar Rectangles
This activity shows how the ratios of perimeters and the ratios of areas of similar rectangles compare to the similarity ratios.https://education.ti.com/en/activity/detail/investigation-of-similar-rectangles
Exterior Angle Theorem
In the activity, you will investigate the relationship found between an exterior angle of a triangle and its related remote interior angles.https://education.ti.com/en/activity/detail/exterior-angle-theorem
Factoring Special Cases
Students explore geometric proofs for two factoring rules: a2 + 2ab + b2 = (a + b)2 and x2 – a2 = (x – a)(x + a). Given a set of shapes whose combined areas represent the left-hand expression, they manipulate them to create rectangles whose areas are equal to the right-hand expression.https://education.ti.com/en/activity/detail/factoring-special-cases_1
Inscribed and Central Angles in a Circle
This activity explores the relationship between inscribed angles subtended by the same minor arc. The second problem explores the relationship between inscribed angles and central angles subtended by the same minor arc.https://education.ti.com/en/activity/detail/inscribed-and-central-angles-in-a-circle