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Unit 7: Equation Detective Agency Lesson 7-7 6.NOS.9

Represent Polygons on the Coordinate Plane

I can draw polygons from their vertex coordinates on the coordinate plane, and use coordinates to find side lengths and solve perimeter and area problems.

Speaking and writing goal: I can explain how I found a distance using the words vertices, coordinates, and absolute value.

What Your Child Is Learning

In this lesson, students practice how to draw polygons from their vertex coordinates on the coordinate plane, and use coordinates to find side lengths and solve perimeter and area problems. They learn to show their thinking with numbers, pictures, words, or a model. The goal is not just getting an answer. Students should be able to explain why the answer makes sense.

Why This Matters

Geometry helps with building, decorating, packing, maps, art, and design. Students use it when they plan space, compare shapes, or figure out how much material a project needs.

What It May Look Like In Class

Your child may use the interactive lesson, guided notes, examples from the board, partner talk, and short practice problems. They may be asked to solve, draw a model, label important numbers, and explain their reasoning in a sentence.

How You Can Help At Home

You do not need to teach a new method. Ask your child to read the problem out loud, circle the important numbers, and explain what they tried first. Helpful questions include: What do you know? What are you trying to find? Does your answer make sense?

Apoyo para familias en español

Qué está aprendiendo su hijo/a

En esta lección, su hijo/a practica medir y resolver problemas de geometría. Puede usar dibujos, números, palabras o modelos para mostrar su pensamiento. Lo más importante es que pueda explicar por qué su respuesta tiene sentido.

Por qué es importante

La geometría se usa para construir, decorar, empacar, leer mapas y diseñar. Ayuda a planear espacios y calcular materiales.

Cómo puede ayudar en casa

No necesita ser experto/a en matemáticas. Pídale a su hijo/a que lea el problema en voz alta, marque los números importantes y explique su primer paso. Puede preguntar: ¿Qué sabes? ¿Qué necesitas encontrar? ¿Tu respuesta tiene sentido?

Key Vocabulary

vertex vértice

A corner point of a polygon, named by an ordered pair on the coordinate plane.

Example: The rectangle's corners are at (-4.5, 3), (5, 3), (5, -3.75), (-4.5, -3.75).

polygon polígono

A closed figure made of line segments; on the plane you draw it by plotting the vertices and connecting them in order.

Example: Plot the four points, connect them, and the rectangle appears.

perimeter perímetro

The total distance around a polygon — the sum of all its side lengths.

Example: 2(9.5) + 2(6.75) = 32.5 units.

distance between vertices distancia entre vértices

When two vertices share an x- or y-coordinate, the distance between them is the absolute difference of the other coordinates.

Example: From (5, 3) to (5, -3.75): |3 − (−3.75)| = 6.75.

scale escala

What one grid unit stands for in the real situation.

Example: Each unit is 100 feet, so 3 units of width is 300 feet.

Try It Together

Pick one or two problems. Let your child explain the first step before opening the answer.

  1. A rectangle is 7 ft by 4 ft. What is its area?
    Show answer

    28 square feet

  2. A parallelogram has base 9 cm and height 3 cm. What is its area?
    Show answer

    27 square centimeters

  3. Name two units that could measure area.
    Show answer

    Square inches, square feet, square centimeters, or similar

  4. Why is labeling units helpful?
    Show answer

    It shows what the number measures and helps catch mistakes.