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

Question

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

Video Solution

Solution Steps

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 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.

Answer

62x 6\sqrt{2}x cm²