Learn with Amar
Teaching video
A teaching recording for this chapter has not been published yet. Start with the worked example below and explore the related animations where available.
Grade 6 chapters and video availability01 · Read and understand
What you will learn
- Explain why parallelogram area uses base times perpendicular height.
- Explain your method and check what the result means in the stated situation.
Before you start
Fraction and decimal operations, whole-number factors, measurement units, and reading simple tables.
Keep paper nearby. Read the question once for the context, then again to identify what is known and what you need to find.
Start with a question
A parallelogram has base 9 m, perpendicular height 4 m, and sloping side 5 m. Find its area.
Why this math matters
Use cutting and rearranging to justify an area formula instead of memorizing it alone. The worked example shows how to connect the situation, its mathematical representation, and a check on the result.
Set up the model
A useful answer starts with clear assumptions:
- Use the units, grouping rules, and reference whole stated in the question.
- Treat the supplied counts and measurements as exact within the classroom model, unless an estimate or a random outcome is requested.
02 · Work through the example
Follow the reasoning, one step at a time.
Try to predict the next step before reading it. After each calculation, explain why the operation makes sense and how it helps answer the original question.
Work through it with Amar
See this example unfold.
The complete worked example, one idea at a time.
Slide a triangle to measure a parallelogram
PausedQuestion: Start with the question. Paused.
Question
Start with the question
A parallelogram has base 9 m, perpendicular height 4 m, and sloping side 5 m. Find its area.
Before you calculate
Read what is known and what you need to find. Make a prediction before moving to the first calculation.
Starts paused. Play advances through the full text at a reading pace; pause whenever you need more time. Previous, Next, and the phase buttons let you set your own pace. Playback pauses when this walkthrough leaves the screen or you switch tabs.
Your device’s reduced-motion setting keeps each phase still. Manual controls remain available. The full written solution stays below.
Represent the situation
Cut a triangular end and move it to the other side
This rearrangement preserves area and forms a rectangle.
Connect the parts
Rectangle dimensions: 9 m by 4 m
The height is the perpendicular separation of the parallel bases.
State and check the result
Area = 9 × 4 = 36 m²
The sloping side five is irrelevant to this area calculation.
The result
Area = 9 × 4 = 36 m²
The sloping side five is irrelevant to this area calculation.
Common mistakes to catch
- Slant length is not generally the height.
- A tilt can change perimeter while leaving base and height unchanged.
03 · Practice independently
Try it before revealing the answer.
Use paper or a calculator as needed. Write your units and reasoning, then open the hint or explanation to check your approach.
Practice 1
Find area with base 7 cm and height 3.5 cm.
Show a hint
Multiply perpendicular dimensions.
Reveal answer and explanation
24.5 cm²
7 × 3.5 = 24.5.
Practice 2
If a parallelogram leans more but keeps the same base and perpendicular height, does area change?
Show a hint
Compare its rearranged rectangle.
Reveal answer and explanation
No
The covering still rearranges to the same base-by-height rectangle.
Take the idea with you
Use cutting and rearranging to justify an area formula instead of memorizing it alone.
04 · Reflect and continue
Can you explain it in your own words?
Before moving on, explain the main idea without looking at the worked example. Try both practice questions, check your reasoning, and name one mistake you now know how to avoid. Return to a step if you still need support.
Up next: Average the parallel sides of a trapezoid
Completion is your own study record, not a test score. It stays in this browser, does not sync to another device, and can be removed by clearing browser data.