Calculate Kite Area: Square Diagonal 36 cm² and AC = 2x

Kite Area with Square Diagonal Properties

ABCD is a kite.

BD is the diagonal of a square that has an area equal to 36 cm².

AC=2x AC=2x

Express the area of the kite in terms of X.

AAABBBCCCDDD

❤️ 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
00:00 Express the deltoid area using X
00:03 Draw a square whose diagonal is BD
00:12 Mark the square's side length as A
00:18 Use the formula for square area to find A
00:21 This is the size of A
00:26 Use the Pythagorean theorem to find BD
00:38 This is the size of BD
00:54 Now use the formula for deltoid area
00:58 (diagonal times diagonal) divided by 2
01:03 Substitute appropriate values and solve for the area
01:09 Simplify where possible
01:15 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

ABCD is a kite.

BD is the diagonal of a square that has an area equal to 36 cm².

AC=2x AC=2x

Express the area of the kite in terms of X.

AAABBBCCCDDD

2

Step-by-step solution

To solve this problem, we'll follow these steps:

  • Step 1: Calculate the side length of the square using the given area.
  • Step 2: Determine the length of BDBD using the side length.
  • Step 3: Use the kite area formula with diagonals BDBD and AC=2xAC=2x.

Now, let's work through each step:

Step 1: The area of the square is 36 cm². The side length of the square, denoted as ss, can be calculated by taking the square root of the area:

s=36=6 cms = \sqrt{36} = 6 \text{ cm}

Step 2: To find diagonal BDBD, we use the relationship for the diagonal of a square in terms of its side:

BD=s2BD = s \sqrt{2}. Given s=6s = 6, we compute:

BD=62 cmBD = 6\sqrt{2} \text{ cm}

Step 3: Now, we apply the formula for the area of a kite, which is 12×d1×d2\frac{1}{2} \times d1 \times d2, where d1=BD=62d1 = BD = 6\sqrt{2} and d2=AC=2xd2 = AC = 2x:

The area AA of the kite is:

A=12×62×2x=62x cm2A = \frac{1}{2} \times 6\sqrt{2} \times 2x = 6\sqrt{2}x \text{ cm}^2

Therefore, the area of the kite in terms of xx is 62x6\sqrt{2}x cm².

3

Final Answer

62x 6\sqrt{2}x cm²

Key Points to Remember

Essential concepts to master this topic
  • Square Diagonal: Diagonal equals side length multiplied by 2 \sqrt{2}
  • Technique: From area 36 cm², side = 6 cm, so BD = 62 6\sqrt{2} cm
  • Check: Area = 12×62×2x=62x \frac{1}{2} \times 6\sqrt{2} \times 2x = 6\sqrt{2}x cm² ✓

Common Mistakes

Avoid these frequent errors
  • Using the square's side length as the diagonal BD
    Don't use BD = 6 cm directly from the square's side = wrong answer 6x! The diagonal of a square is longer than its side. Always multiply the side length by 2 \sqrt{2} to get the diagonal: BD = 62 6\sqrt{2} cm.

Practice Quiz

Test your knowledge with interactive questions

Look at the triangle in the diagram. How long is side AB?

222333AAABBBCCC

FAQ

Everything you need to know about this question

Why is the diagonal of a square not equal to its side length?

+

A diagonal cuts across the square from corner to corner, creating a right triangle. Using the Pythagorean theorem with two sides of length 6: d2=62+62=72 d^2 = 6^2 + 6^2 = 72 , so d=72=62 d = \sqrt{72} = 6\sqrt{2} .

How do I know which diagonal is which in the kite?

+

The problem tells us BD is the diagonal of a square, so BD has the special square property. AC is the other diagonal with length 2x 2x .

What's the formula for kite area again?

+

Kite area = 12×d1×d2 \frac{1}{2} \times d_1 \times d_2 where d1 d_1 and d2 d_2 are the lengths of the two diagonals. The diagonals of a kite are always perpendicular!

Why don't we need to know the actual value of x?

+

The question asks for the area in terms of x, meaning we leave x as a variable in our final answer. We express the relationship between the area and x: 62x 6\sqrt{2}x cm².

Can I simplify 62x 6\sqrt{2}x further?

+

No, 62x 6\sqrt{2}x is already in its simplest form. You cannot combine the radical 2 \sqrt{2} with the other terms because they're different types of numbers.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Deltoid 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