+
Activity
Texas Instruments

Texas Instruments: Altitude, Median, and Angle Bisector of a Triangle

For Teachers 9th - 10th
In this activity, you will construct special segments of a triangle named altitudes, medians, and angle bisectors, Using their definitions. You will look at how an altitude, a median, and an angle bisector divide the area of a triangle....
+
Activity
Texas Instruments

Texas Instruments: Investigating Segments in a Right Triangle

For Teachers 9th - 10th Standards
In this activity, students review definitions of terms such as right triangle, hypotenuse, midpoint, vertices, and equidistant. They also discover an important characteristic of the midpoint of the hypotenuse.
+
Activity
Texas Instruments

Texas Instruments: Midsegment of a Triangle

For Teachers 9th - 10th Standards
Students explore the properties of triangles formed by connecting the midpoints of two sides of a triangle, and examine the relationship between the two triangles. They study the Triangle Midsegment theorem. [Requires Adobe Reader.]
+
Activity
Texas Instruments

Texas Instruments: Cottage Water Problem

For Teachers 9th - 10th
Students use the Cabri Geometry II Plus software to solve a geometry problem. They move the vertex point that is common to two right triangles along the base to find the smallest possible sum of the length of the hypotenuse.
+
Activity
Texas Instruments

Texas Instruments: Triangle Inequality

For Teachers 9th - 10th
In this activity the Students can use Cabri Jr. to investigate the Triangle Inequality Theorm and make conjectures about their findings.
+
Activity
Texas Instruments

Texas Instruments: Looking for Mr. Right Triangle

For Teachers 9th - 10th Standards
Navigator Activity: This is a review of the right triangle in the coordinate plane. Given two lines (2 really nice ones) the students write the equation of the 3rd line to create a right triangle. They find the vertices of the triangle...
+
Activity
Texas Instruments

Texas Instruments: Does Your Euler Line "Wiggle"?

For Teachers 9th - 10th
The students will construct an Euler line and demonstrate it is an Euler line by "wiggling" the triangle to guarantee the correct centers remain on the line.
+
Activity
Texas Instruments

Texas Instruments: Ratios in Right Triangles

For Teachers 9th - 10th Standards
The study of properties of right triangles is a major topic in mathematics. In this activity, you will investigate three common right triangle trigonometric ratios. [Requires Adobe Reader.]
+
Activity
Texas Instruments

Texas Instruments: Triangles

For Teachers 9th - 10th Standards
This file contains questions related to triangles. The questions can be used to asses your students' understanding of this topic in geometry.
+
Activity
Texas Instruments

Texas Instruments: Mc Dougal Littell Geometry: Investigate Proportionality

For Teachers 9th - 10th Standards
Students can use the TI-84 Plus family with Cabri Jr. to segment lengths in a triangle.
+
Activity
Texas Instruments

Texas Instruments: Measuring Angles in a Triangle

For Teachers 9th - 10th Standards
In this activity, students learn about the sum of the angles in a triangle. They understand triangles and their interior angles.
+
Activity
Texas Instruments

Texas Instruments: Triangle Midsegment Theorem

For Teachers 9th - 10th Standards
Students can use Cabri Jr. to discover that the midsegment of a triangle is parallel to the third side and half the length of the third side.
+
Activity
Texas Instruments

Texas Instruments: Triangulation Problem

For Teachers 9th - 10th Standards
In this Computer Algebra System (CAS) activity, students use 'landscape' paper and fold the top left corner of the page so that it just touches the bottom of the page. They calculate the area of the triangle formed by the bottom left...
+
Activity
Texas Instruments

Texas Instruments: Dynamic Geometry: Basic Constructions

For Teachers 6th - 8th Standards
Students use the Cabri Jr. application to draw triangles and construct perpendicular bisectors on the sides of a triangles. They study the properties of a triangle and understand how the measures of angles of a triangle is always 180...
+
Activity
Texas Instruments

Texas Instruments: Right Triangles Are Cool Because of Pythag's Rule

For Teachers 9th - 10th Standards
In this activity, students use the Geoboard to determine the length of the sides of a right triangles. [Requires Adobe Reader.]
+
Activity
Texas Instruments

Texas Instruments: Right Triangle Trig

For Teachers 9th - 10th Standards
This is a way to use the TI-Navigator to check for an understanding of sin, cos, and tan before you move onto word problems.
+
Activity
Texas Instruments

Texas Instruments: The Orthocenter of a Triangle

For Teachers 9th - 10th Standards
Students understand that the orthocenter is the point of concurrence of the three altitudes of a triangle. They construct circumcircles and Feuerbach circles and determine the relationship between them.
+
Activity
Texas Instruments

Texas Instruments: Is an Equilateral Triangle a Special Case of Isosceles?

For Teachers 6th - 8th
The definition of isosceles triangle can determine whether an equilateral triangle is a special case of an isosceles triangle. Using the Cabri Jr. application, students can get a feel for which definition makes the most sense. Along the...
+
Activity
The Math League

The Math League: Area and Perimeter

For Students 9th - 10th Standards
This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.
+
Lesson Plan
Ministry of Education and Universities of the Region of Murcia (Spain)

Ministerio De Educacion Y Ciencia: Rectas Notables De Un Triangulo

For Teachers 9th - 10th Standards
In Spanish. Interactive activities dealing with the concept of angle bisector, median and altitude of a triangle. A description of the circumcenter and centroid are given along with a visual representation. [Requires Java.]
+
Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Counting Rectangle,s Squares, Circles, and Triangles in Sets

For Students 1st - 2nd Standards
[Free Registration/Login may be required to access all resource tools.] The video displays a set of figures and reviews triangles by number of sides. Then all of the triangles out of the set of figures are chosen. The video is followed...
+
Lesson Plan
PBS

Pbs Mathline Lesson Plan: Struts'n Stuff [Pdf]

For Teachers 3rd - 5th Standards
Incorporating concepts in algebra, number sense, patterning, data collection, and geometry, this lesson engages students in various hands-on activities to explore the relationship between regular polygons and the number of diagonals...
+
Study Guide
SEDL

The Timss Mathematics Segment: Geometry

For Students 4th - 8th Standards
This site explores the area of congruent triangles and how it is a difficult area to understand.
+
Website
PBS

Classics for Kids: Musical Instruments

For Students 3rd - 8th
An A-to-Z directory of all the instruments and tools of the orchestra. Each entry includes a description, a picture, and a sound sample.