Curated OER
Proposed Problems
In this math worksheet, students read the information about an isosceles triangle. The ratio of the lengths of two sides is equal. They determine the exact measures of its angles.
Curated OER
Triangle Side Lengths and Angles Measures
Students identify missing sides and angles. In this geometry lesson, students use triangular theorems to identify the missing sides. They use the Pythagorean Theorem to find the different ratios of each side.
Curated OER
Inscribing a Square in a Circle
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
Curated OER
Midpoints
In this midpoints worksheet, 10th graders solve and complete 10 different problems. First, they find the perimeter of each illustrated triangle. Then, students determine the bases and median of a trapezoid. They also prove that two lines...
Curated OER
The Sum of All Angles
Learners add up the different angles using the angle addition postulate. In this geometry lesson plan, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show...
Curated OER
Proofs in Coordinate Geometry
In this coordinate geometry activity, learners identify the lengths of a quadrilateral and find the slope of a line. They use proofs to identify the characteristics of given quadrilaterals. This one-page activity contains ten problems.
Curated OER
Polygons All Around Us!
Young scholars explore the concept of polygon properties. In this polygon properties lesson, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Young scholars identify different geometric...
Oswego City School District
Regents Exam Prep Center: Isosceles Triangle Theorem
Material to supplement instruction on isosceles triangles: a lesson with related theorems and examples; an online practice quiz for students to take and check their answers; and guidelines for proving the isosceles triangle theorem.
Illustrative Mathematics
Illustrative Mathematics: g.co Reflections and Isosceles Triangles
This task has learners link their intuitive notions of symmetries of a triangle with statements proving that said triangle is unmoved by applying certain rigid transformations. The mechanism through which students do this is via...