Standard 4: TrianglesArchived

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Identify and describe various kinds of triangles (right, acute, scalene, isosceles, etc.). Define and construct altitudes, medians, and bisectors, and triangles congruent to given triangles. Prove that triangles are congruent or similar and use properties of these triangles to solve problems involving lengths and areas. Relate geometry to algebra by using coordinate geometry to determine regularity, congruence, and similarity. Understand and apply the inequality theorems of triangles.
General Information
Number: MA.912.G.4
Title: Triangles
Type: Standard
Subject: X-Mathematics (former standards - 2008) - Archived
Grade: 912
Body of Knowledge: Geometry

Related Benchmarks

This cluster includes the following benchmarks.

Related Access Points

This cluster includes the following access points.

Independent

MA.912.G.4.In.a
Discriminate between triangles that have equal sides and angles (equilateral), triangles that have two equal sides and two equal angles (isosceles), and triangles that have one right angle (right triangle) using visual and physical models.
MA.912.G.4.In.b
Identify the height (altitude) in equilateral and isosceles triangles using physical and visual models.
MA.912.G.4.In.c
Measure sides and angles of triangles to determine whether triangles are the same size and shape (congruent) or the same shape, but different size (similar).

Supported

MA.912.G.4.Su.a
Discriminate between triangles that have equal sides and angles (equilateral) and triangles that have two equal sides and two equal angles (isosceles) using physical models.
MA.912.G.4.Su.b
Measure the length of sides of triangles to verify if two triangles are the same shape and size (congruent).

Participatory

MA.912.G.4.Pa.a
Identify objects, pictures, or signs with a triangle in real-world situations.
MA.912.G.4.Pa.b
Match two or more objects with a triangle based on a given feature, such as the length of the side or size of the angle, in real-world situations.

Related Resources

Vetted resources educators can use to teach the concepts and skills in this topic.

Image/Photograph

Clipart: Geometric Shapes:

In this lesson, you will find clip art and various illustrations of polygons, circles, ellipses, star polygons, and inscribed shapes.

Type: Image/Photograph

Lesson Plans

Intersecting Medians and the Resulting Ratios:

This lesson leads students to discover empirically that the distance from each vertex to the intersection of the medians of a triangle is two-thirds of the total length of each median.

Type: Lesson Plan

Detemination of the Optimal Point:

Students will use dynamic geometry software to determine the optimal location for a facility under a variety of scenarios. The experiments will suggest a relation between the optimal point and a common concept in geometry; in some cases, there will be a connection to a statistical concept. Algebra can be used to verify some of the conjectures.

Type: Lesson Plan

Student Resources

Vetted resources students can use to learn the concepts and skills in this topic.

Parent Resources

Vetted resources caregivers can use to help students learn the concepts and skills in this topic.

Image/Photograph

Clipart: Geometric Shapes:

In this lesson, you will find clip art and various illustrations of polygons, circles, ellipses, star polygons, and inscribed shapes.

Type: Image/Photograph