Determine the Area of Parallelograms and Rhombuses
Name Period
Objectives / Objetivos
Content Objective: I can find the area of a parallelogram using base × height.
Language Objective: I can explain how I found the area using the words base, height, area, and formula.
Key Idea / Idea clave
Area of Parallelograms & Rhombuses. Formula: Area = Base × Height (A = b · h). 1. Identify the base (any side). 2. Identify the perpendicular height (height must be perpendicular to base, not slanted). 3. Multiply base times height; label with square units (e.g. cm², in²)
I Notice / Observo
- What shape is the patio?
- What measurements are given?
I Wonder / Me pregunto
- Why do we use the height instead of the slanted side to find the area?
Vocabulary / Vocabulario
| Term / Término | Definition / Definición |
|---|---|
| Area of Parallelograms Área de paralelogramos | The space inside a parallelogram. Formula: A = b × h, using the perpendicular height. El espacio dentro de un paralelogramo. Fórmula: A = b × h, usando la altura perpendicular. |
| Slanted side Lado inclinado | A side that leans instead of going straight up and down. It is not the perpendicular height. Un lado que está inclinado en vez de subir y bajar verticalmente. No es la altura perpendicular. |
| Parallelogram Paralelogramo | A four-sided shape with two pairs of parallel sides. Una figura de cuatro lados con dos pares de lados paralelos. |
| Parallel Paralelas | Two lines or sides that stay the same distance apart and never meet. Dos líneas o lados que se mantienen a la misma distancia y nunca se cruzan. |
| Base Base | Any side of a parallelogram can be the base. Once you pick a base, the height must be measured perpendicular (at a 90° angle) to it. Cualquier lado de un paralelogramo puede ser la base. Una vez que eliges la base, la altura debe medirse perpendicular (en un ángulo de 90°) a ella. |
| Height Altura | The straight-up distance from the base to the top. La distancia recta hacia arriba desde la base hasta la parte de arriba. |
Practice Preview / Vista previa de práctica
Read each task. Show your work in the spaces provided and explain how you know.
1. What is the area of a parallelogram with base 10 cm and height 7 cm?
- A 17 sq cm
- B 34 sq cm
- C 70 sq cm
- D 70 cm
Answer:
2.
Complete each empty cell. Show your reasoning below.
| Parallelogram | Base | Height | Area |
|---|---|---|---|
| Patio A | 14 ft | 9 ft | |
| Patio B | 8 ft | 56 sq ft | |
| Patio C | 12 ft | 96 sq ft | |
| Patio D | 15 ft | 6 ft |
3. Match each shape to its area.
Write the letter of the matching item in the blank.
| 1. | Triangle 8×6 | A. | 40 sq units | |
| 2. | Parallelogram 5×4 | B. | 20 sq units | |
| 3. | Rectangle 7×3 | C. | 36 sq units | |
| 4. | Triangle 10×8 | D. | 18 sq units | |
| 5. | Square side 6 | E. | 24 sq units | |
| 6. | Parallelogram 9×2 | F. | 21 sq units |
4. Find the Area Error
Which step has the mistake, and what should it be?
Reflection / Reflexión
One thing I learned today / Una cosa que aprendí hoy: