**TEKS OBJECTIVES**

(8) Geometry and spatial reasoning. The student identifies and describes attributes of geometric figures using formal geometric language. The student is expected to:

(A) identify and describe right, acute, and obtuse angles;

(B) identify and describe parallel and intersecting (including perpendicular) lines using concrete objects and pictorial models;

(C) use essential attributes to define two- and three-dimensional geometric figures.

(9) Geometry and spatial reasoning. The student connects transformations to congruence and symmetry. The student is expected to:

(A) demonstrate translations, reflections, and rotations using concrete models;

(B) use translations, reflections, and rotations to verify that two shapes are congruent; and

(C) use reflections to verify that a shape has symmetry.

(A) identify and describe right, acute, and obtuse angles;

(B) identify and describe parallel and intersecting (including perpendicular) lines using concrete objects and pictorial models;

(C) use essential attributes to define two- and three-dimensional geometric figures.

(9) Geometry and spatial reasoning. The student connects transformations to congruence and symmetry. The student is expected to:

(A) demonstrate translations, reflections, and rotations using concrete models;

(B) use translations, reflections, and rotations to verify that two shapes are congruent; and

(C) use reflections to verify that a shape has symmetry.

**Resources**

1. Students are expected to learn and identify right, acute, and obtuse angles. Khan Academy has a great tutorial for recognizing right, acute, and obtuse angles.

2. http://www.superteacherworksheets.com/geometry/angles_TTZZR.pdf. Super Teacher Worksheets has plenty of worksheets focusing on learning the three types of angles. Worksheets also include assessments for the end of the lesson. The website also provides the answer key for the teachers.