5.1 Small Group · Group 1
Tier 2 Intervention · Concrete-Representational-Abstract (CRA) · Dual-Language Anchors
Area of Parallelograms · Slanted side · Procedural Fluency · Real-World Applications
- A parallelogram is a four-sided shape with two pairs of parallel sides, like a leaning rectangle. Its area is how much flat space is inside it. We'll walk through a worked example, try one together, then you'll try a few with hints right there when you need them.
- I have a parallelogram with a base of 14 feet and a height of 9 feet.
- I write the formula: A = base × height.
- I put in the numbers: A = 14 × 9.
- I multiply: 14 × 9 = 126.
- So the area is 126 square feet. I used the height of 9, not the slanted side.
- Area of Parallelograms (Área de paralelogramos) — The space inside a parallelogram. Formula: A = b × h, using the perpendicular height.
- Slanted side (Lado inclinado) — A side that leans instead of going straight up and down. It is not the perpendicular height.
- Parallelogram (Paralelogramo) — A four-sided shape with two pairs of parallel sides.
- Parallel (Paralelas) — Two lines or sides that stay the same distance apart and never meet.
- 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.
- Height (Altura) — The straight-up distance from the base to the top.
- The most common mistake in Area of Parallelograms is multiplying the base by the slanted side instead of the perpendicular height. For a parallelogram with a base of 16 ft, a perpendicular height of 9 ft, and a slanted side of 11 ft, students compute 16 × 11 = 176 square feet instead of the correct 16 × 9 = 144 square feet. The height must be the straight-up (perpendicular) distance between the base and its opposite side, not the length of the slanted side, even though the slanted side is often the number that 'looks' like it belongs in the formula.
-
1 FILL TABLE
Use the formula A = b × h to find the area of each parallelogram.
Parallelogram Base Height Area Patio X Patio Y ✏️ Scratchpad / Reasoning -
2 FILL TABLE
Solve the mathematical problem. Show all of your work and reasoning.
Parallelogram Base Height Area Patio A Patio B Patio C Patio D ✏️ Scratchpad / Reasoning
-
3 MULTIPLE CHOICE
What is the area of a parallelogram with base 10 cm and height 7 cm?
- A70 sq cm
- B34 sq cm
- C17 sq cm
- D70 cm
FormulaPut the numbers inWork it outAnswer with its unit- 1Name itWhich measure is asked?
- 2Write the formulaBefore any numbers.
- 3SubstituteMatch each letter.
- 4Unitunits, sq units, or cubic?
-
4 MULTIPLE CHOICE
A parallelogram has an area of 54 sq ft and a base of 9 ft. What is the height?
- A6 ft
- B45 ft
- C63 ft
- D27 ft
FormulaPut the numbers inWork it outAnswer with its unit- 1Name itWhich measure is asked?
- 2Write the formulaBefore any numbers.
- 3SubstituteMatch each letter.
- 4Unitunits, sq units, or cubic?
-
5 MULTIPLE CHOICE
What is the area of a parallelogram with base 9 cm and height 5 cm?
- A45 sq cm
- B14 sq cm
- C22.5 sq cm
- D90 sq cm
FormulaPut the numbers inWork it outAnswer with its unit- 1Name itWhich measure is asked?
- 2Write the formulaBefore any numbers.
- 3SubstituteMatch each letter.
- 4Unitunits, sq units, or cubic?
-
6 MULTIPLE CHOICE
Which measurement is the height of a parallelogram?
- AThe perpendicular distance between the base and the opposite side
- BThe length of the slanted side
- CThe perimeter divided by 4
- DThe longest side
✏️ Workspace & Solution Steps
Group Discussion Prompt: How does your visual model justify your mathematical solution?
Partner A: "I modeled this by identifying the relationship and..."
Partner B: "I agree with your step because the standard mathematical rule states..."
Complete each sentence stem to demonstrate precise mathematical reasoning:
Writing Task: Justify why your mathematical solution is accurate and complete.