Area of Trapezoids

6.GR.1 · Unit 5 · Lesson 2

Name   Period

Objectives / Objetivos

Content Objective: I can find the area of a trapezoid using the formula A = ½(b1 + b2) × h.

Language Objective: I can explain my steps using the words trapezoid, base, height, and area.

Key Idea / Idea clave

Area of a trapezoid = ½ × (base 1 + base 2) × height. We add the two bases first, then take half.

I Notice / Observo

  • What shape is the window?
  • How many parallel sides does it have?

I Wonder / Me pregunto

  • Why does the formula use two bases instead of one?

Vocabulary / Vocabulario

Term / TérminoDefinition / Definición
Trapezoid
Trapecio		A four-sided shape with just one pair of parallel sides.
Una figura de cuatro lados con solo un par de lados paralelos.
Base 1 (b1)
Base 1 (b1)		One of the two parallel sides of a trapezoid.
Uno de los dos lados paralelos de un trapecio.
Base 2 (b2)
Base 2 (b2)		The other parallel side of a trapezoid.
El otro lado paralelo de un trapecio.
Height
Altura		The straight-up distance between the two parallel sides.
La distancia recta entre los dos lados paralelos.
Area
Área		How much space is inside a flat shape.
Cuánto espacio hay dentro de una figura plana.

Practice Preview / Vista previa de práctica

  1. What is the area of a trapezoid with bases 6 cm and 10 cm, and height 4 cm?
    1. 32 sq cm
    2. 64 sq cm
    3. 24 sq cm
    4. 40 sq cm
  2. Problem 2
  3. Match each shape to its area.
  4. Find the Area Error
    1. Step 1: Identify the bases and height — b₁ = 10 m, b₂ = 6 m, h = 7 m
    2. Step 2: Write the formula — A = ½ × (b₁ + b₂) × h
    3. Step 3: Substitute values — A = ½ × (10 + 6) × 7
    4. Step 4: Calculate — A = (10 + 6) × 7 = 112 sq m

    Which step has the mistake? Explain it and write the correct work.

Reflection / Reflexión

One thing I learned today / Una cosa que aprendí hoy: