Directions: Use the whole numbers 1 through 6, at most one time each, to find three side lengths that are two-digits each and form an acute triangle. Source: Samantha Cruz

Read More »# High School: Geometry

## Area of Three Triangles

Directions: Use the integers 2 through 10, at most one time each, as lengths of individual sides to form three triangles. What is the smallest total area of the three triangles you can create? What is the largest? Source: Dan Wulf

Read More »## Area of a Triangle in the Coordinate Plane

Directions: Use the digits 0 to 9, at most one time each, to fill in ordered pairs for all three points, such that the area of Triangle ABC is closest to 6 square units. A ( ___, ___ ) B ( ___, ___ ) C ( ___, ___ ) Source: Henry Wadsworth

Read More »## Transformations

Directions: Given triangle ABC with vertices (-8,2), (-2,2), and (-2, 8), create triangle DEF in quadrant one that uses a translation, rotation, and reflection (in any order) to take that triangle to triangle ABC and show congruence. Source: Jon Henderson

Read More »## Midpoint Formula

Directions: Create two pairs of coordinates on the same line segment that have M (3,4) as their midpoint. Source: Dane Ehlert

Read More »## Coordinate Parallelograms

Directions: Fill in the x and y coordinates using whole numbers 1-9, without repetition, so that the points make a parallelogram. Source: Daniel Torres-Rangel

Read More »## Perpendicular lines through a given point

Directions: Using the numbers 0 through 9, at most one time each, fill in the boxes to create a correct statment: Source: Andy Schwen

Read More »## Creating Right Triangles 2

Directions: Using only the whole numbers 1 through 8 (without repeating any number), fill in the coordinates to create the vertices of a right triangle: A(__, __), B(__, __), C(__, __) Extension: Try to do this using only the whole numbers 1 through 6. Source: Erick Lee

Read More »## Creating Rectangles 2

Directions: Using only the whole numbers 1 through 8 (without repeating any number), fill in the coordinates to create the vertices of a rectangle: A(__, __), B(__, __), C(__, __), D(__, __). Extension: What is the rectangle with the largest/smallest area/perimeter that you can find? Source: Erick Lee

Read More »## Line of Reflections on Isosceles Triangles

Directions: How many ways can you determine the location of the line of reflection for isosceles triangle XYZ that maps Point X to Point Z? Source: Irvine Math Project, Nanette Johnson, and Robert Kaplinsky.

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