Aspect ratio in CSS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a fixed aspect ratio of 16:9 on the box.

CSS

div {
  aspect-ratio: [1];
  background-color: lightblue;
  width: 300px;
}

Drag options to blanks, or click blank then click option'

A4/3

B9/16

C1/1

D16/9

Attempts:

3 left

💡 Hint

Common Mistakes

Using 9/16 instead of 16/9 reverses the ratio.

Forgetting to use a slash between numbers.

The aspect-ratio property accepts a ratio like 16/9 to keep the width and height proportional.

2fill in blank

medium

Complete the code to keep the aspect ratio of the image container at 4:3.

CSS

.image-container {
  aspect-ratio: [1];
  width: 400px;
  background-color: #ddd;
}

Drag options to blanks, or click blank then click option'

A4/3

B3/4

C16/9

D1/1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3/4 instead of 4/3 flips the ratio.

Using 16/9 which is a different ratio.

Setting aspect-ratio: 4/3; keeps the container width to height ratio as 4 to 3.

3fill in blank

hard

Fix the error in the CSS to correctly apply a 1:1 aspect ratio.

CSS

.square {
  aspect-ratio: [1];
  width: 200px;
  background-color: coral;
}

Drag options to blanks, or click blank then click option'

A1-1

B1:1

C1/1

Dsquare

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1:1 or 1-1 instead of 1/1.

Using a named value like 'square' which is invalid.

The correct syntax for aspect ratio uses a slash, like 1/1, not a colon or dash.

4fill in blank

hard

Fill both blanks to create a responsive video container with a 16:9 aspect ratio and a max width of 600px.

CSS

.video-container {
  aspect-ratio: [1];
  max-width: [2];
  background-color: black;
}

Drag options to blanks, or click blank then click option'

A16/9

B600px

C400px

D4/3

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping aspect ratio values.

Using width instead of max-width.

Use aspect-ratio: 16/9; for widescreen and max-width: 600px; to limit container size.

5fill in blank

hard

Fill all three blanks to create a card with a 3:2 aspect ratio, a width of 300px, and a light gray background.

CSS

.card {
  aspect-ratio: [1];
  width: [2];
  background-color: [3];
}

Drag options to blanks, or click blank then click option'

A3/2

B300px

Clightgray

D2/3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2/3 instead of 3/2 flips the ratio.

Using 'gray' instead of 'lightgray' for background.

The card uses aspect-ratio: 3/2; for width to height ratio, width: 300px; for size, and background-color: lightgray; for color.

Practice

1. What does the CSS property aspect-ratio do for an element?

easy

A. It keeps the element's width and height in a fixed ratio to avoid stretching.

B. It changes the element's color based on its size.

C. It hides the element when the screen is too small.

D. It adds a border around the element.

Solution

1. Step 1: Understand the purpose of aspect-ratio

   The property controls the ratio between width and height to keep the shape consistent.

2. Step 2: Identify the effect on element shape

   It prevents the element from stretching or squishing by maintaining the ratio.

3. Final Answer:

   It keeps the element's width and height in a fixed ratio to avoid stretching. -> Option A

4. Quick Check:

   Aspect ratio = fixed width/height ratio [OK]

Hint: Aspect ratio locks shape, not color or visibility [OK]

Common Mistakes:

• Thinking it changes colors
• Assuming it hides elements
• Confusing with border properties

2. Which of the following is the correct syntax to set an aspect ratio of 16:9 in CSS?

easy

A. aspect-ratio: 16:9;

B. aspect-ratio: (16, 9);

C. aspect-ratio: "16/9";

D. aspect-ratio: 16 / 9;

Solution

1. Step 1: Recall the correct syntax format

   The aspect-ratio property uses a ratio with a slash between numbers, no quotes or commas.

2. Step 2: Match the correct option

   aspect-ratio: 16 / 9; uses 16 / 9 which is the correct way to write the ratio.

3. Final Answer:

   aspect-ratio: 16 / 9; -> Option D

4. Quick Check:

   Use slash between numbers for aspect ratio [OK]

Hint: Use slash (/) between numbers, no quotes or commas [OK]

Common Mistakes:

• Using colon instead of slash
• Adding quotes around ratio
• Using parentheses or commas

3. Given this CSS code:

div {
  width: 320px;
  aspect-ratio: 4 / 3;
  background-color: lightblue;
}

What will be the height of the div when rendered in the browser?

medium

A. 480px

B. 240px

C. 320px

D. 213px

Solution

1. Step 1: Understand aspect ratio formula

   The aspect ratio 4 / 3 means width divided by height equals 4/3.

2. Step 2: Calculate height from width

   Height = Width ÷ (4/3) = 320 ÷ (4/3) = 320 x (3/4) = 240px.

3. Final Answer:

   240px -> Option B

4. Quick Check:

   Height = width x (height/width) = 240px [OK]

Hint: Height = width x (height ÷ width) from ratio [OK]

Common Mistakes:

• Dividing height by width instead of width by height
• Using width as height
• Confusing ratio numbers

4. What is wrong with this CSS code if the element does not keep the expected 1:1 aspect ratio?

.box {
  width: 200px;
  aspect-ratio: 1 / 1;
  height: 150px;
  background: coral;
}

medium

A. The fixed height overrides the aspect ratio, causing distortion.

B. The aspect ratio syntax is incorrect.

C. The width must be set in percentages for aspect ratio to work.

D. Background color prevents aspect ratio from applying.

Solution

1. Step 1: Identify conflicting properties

   The CSS sets both width and height explicitly, which conflicts with aspect-ratio.

2. Step 2: Understand aspect-ratio behavior

   When height is fixed, the aspect ratio cannot adjust height automatically, so the shape distorts.

3. Final Answer:

   The fixed height overrides the aspect ratio, causing distortion. -> Option A

4. Quick Check:

   Fixed height blocks aspect ratio adjustment [OK]

Hint: Avoid fixed height when using aspect-ratio [OK]

Common Mistakes:

• Thinking syntax is wrong
• Believing background affects ratio
• Assuming width must be %

5. You want a responsive square div that always stays square regardless of screen size. Which CSS setup achieves this best?

hard

A. width: 50vw; height: auto;

B. width: 50vw; height: 50vh;

C. width: 50vw; aspect-ratio: 1 / 1;

D. width: 50vw; max-height: 50vw;

Solution

1. Step 1: Understand responsive sizing with aspect ratio

   Using width: 50vw; sets width to half the viewport width, and aspect-ratio: 1 / 1; keeps height equal to width, making a square.

2. Step 2: Compare other options

   width: 50vw; height: auto; uses height: auto;, which depends on content. width: 50vw; height: 50vh; uses height: 50vh;, half viewport height, so not square on widescreen monitors. width: 50vw; max-height: 50vw; uses max-height: 50vw;, which caps but doesn't enforce square.

3. Final Answer:

   width: 50vw; aspect-ratio: 1 / 1; -> Option C

4. Quick Check:

   Aspect ratio + responsive width = perfect square [OK]

Hint: Use aspect-ratio with responsive width for perfect squares [OK]

Common Mistakes:

• Setting fixed height instead of aspect ratio
• Using height:auto which breaks square shape
• Confusing max-height with height