Calculate Parallelogram Area Using 4:7 Ratio: Height = 8 Units

Parallelogram Area with Proportional Segments

Shown below is the parallelogram ABCD.

The ratio between AE and DC is 4:7.

Calculate the area of the parallelogram ABCD.

888AAABBBCCCDDDEEE

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:11 Let's find the area of the parallelogram.
00:17 Check the ratio of height to side, using the given data.
00:25 Multiply by DC, to get rid of the fraction.
00:32 Next, multiply by the reciprocal, again to eliminate the fraction.
00:46 Now, set the value for AE using the given data.
00:59 This tells us the size of DC.
01:02 We'll use the formula to find the parallelogram's area.
01:06 Multiply side, DC, by height, AE.
01:10 Plug in the right values, and solve to get the area.
01:14 And that's how we solve the problem!

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Shown below is the parallelogram ABCD.

The ratio between AE and DC is 4:7.

Calculate the area of the parallelogram ABCD.

888AAABBBCCCDDDEEE

2

Step-by-step solution

To find the area of the parallelogram ABCD, follow these steps:

  • Step 1: Assume AE=4x AE = 4x and DC=7x DC = 7x . The ratio between AE and DC is given as 4:7.

  • Step 2: GivenAE=8 AE = 8 cm, we can write: 4x=8 4x = 8 . Solve for x: x=2 x = 2 cm.

  • Step 3: Substitute x=2 x = 2 into DC=7x DC = 7x to find DC: DC=7×2=14 \text{DC} = 7 \times 2 = 14 cm.

  • Step 4: The area of the parallelogram is given by base × \times height. Here, base DC=14 DC = 14 cm and height AE=8 AE = 8 cm, so the area is: Area=14×8=112 cm2.\text{Area} = 14 \times 8 = 112 \text{ cm}^2.

Thus, the area of the parallelogram ABCD is 112 112 cm².

3

Final Answer

112 112 cm².

Key Points to Remember

Essential concepts to master this topic
  • Formula: Area of parallelogram equals base times height
  • Technique: Use ratio 4:7 to find DC = 14 when AE = 8
  • Check: Verify perpendicular height AE creates right angle with base DC ✓

Common Mistakes

Avoid these frequent errors
  • Using the wrong side as the base
    Don't use AE as the base = Area of 8 × 14 = 112, but incorrectly labeled! AE is the perpendicular height, not a side of the parallelogram. Always use DC (the actual side) as the base and AE as the perpendicular height.

Practice Quiz

Test your knowledge with interactive questions

A parallelogram has a length equal to 6 cm and a height equal to 4.5 cm.

Calculate the area of the parallelogram.

6664.54.54.5

FAQ

Everything you need to know about this question

Why is AE the height and not a side of the parallelogram?

+

Point E lies directly below point A, creating a perpendicular line to the base DC. This makes AE the height (perpendicular distance), not a side of the parallelogram.

How do I use the ratio 4:7 to find the actual lengths?

+

Set up the ratio as AE:DC=4x:7x AE:DC = 4x:7x . Since AE = 8, solve 4x=8 4x = 8 to get x=2 x = 2 . Then DC=7×2=14 DC = 7 \times 2 = 14 .

Can I use any side as the base for a parallelogram?

+

Yes! You can use any side as the base, but you must use the perpendicular height to that base. Different base choices give the same area.

What if the ratio was given as 7:4 instead?

+

The calculation method stays the same! Set AE=7x AE = 7x and DC=4x DC = 4x , then solve 7x=8 7x = 8 to find x and calculate DC.

How do I know which measurement is the height?

+

Look for the perpendicular distance between parallel sides. In this diagram, AE forms a right angle with the base, shown by the small square symbol at point E.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Parallelogram questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations