Area of a Geometric Flower: Solving with Variables 2x, 1.2x, and 1.5x

Circle Area Addition with Variable Radii

What is the area of the flower represented in the diagram?

2x321.2x1.5x

❤️ 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 Find the area of the flower
00:03 The area of the flower equals the sum of the circles' areas
00:12 We'll use the formula for calculating circle area
00:24 We'll substitute this formula in the flower's area
00:43 Now we'll substitute appropriate values according to the given data and calculate to find the area
01:03 We'll solve the multiplications
01:15 We'll group the factors
01:18 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

What is the area of the flower represented in the diagram?

2x321.2x1.5x

2

Step-by-step solution

To solve this problem, we'll calculate the areas of the different circles and then add them accordingly. This approach requires determining each circle's area as follows:

  • Identify the radii of the circles given as 2x2x, 1.5x1.5x, 1.2x1.2x, constants like 3, and 2.
  • Use the circle area formula A=πr2A = \pi r^2 to calculate each circle's area.
  • Add all these areas to determine the total area of the flower shape.

Let's begin:

First Circle: Radius =2x= 2x
Area =π(2x)2=4x2π= \pi (2x)^2 = 4x^2\pi

Second Circle: Radius =1.5x= 1.5x
Area =π(1.5x)2=2.25x2π= \pi (1.5x)^2 = 2.25x^2\pi

Third Circle: Radius =1.2x= 1.2x
Area =π(1.2x)2=1.44x2π= \pi (1.2x)^2 = 1.44x^2\pi

Fourth Circle: Radius =3= 3
Area =π(3)2=9π= \pi (3)^2 = 9\pi

Fifth Circle: Radius =2= 2
Area =π(2)2=4π= \pi (2)^2 = 4\pi

Now, summing the areas in terms of π\pi, we find:

Total Area =4x2π+2.25x2π+1.44x2π+9π+4π= 4x^2\pi + 2.25x^2\pi + 1.44x^2\pi + 9\pi + 4\pi
Combine like terms:
Total Area =(4+2.25+1.44)x2π+(9+4)π= (4 + 2.25 + 1.44)x^2\pi + (9 + 4)\pi

Total Area =7.69x2π+13π= 7.69x^2\pi + 13\pi

Therefore, the area of the flower depicted in the diagram is 7.69x2π+13π 7.69x^2\pi+13\pi .

3

Final Answer

7.69x2π+13π 7.69x^2\pi+13\pi

Key Points to Remember

Essential concepts to master this topic
  • Formula: Use A=πr2 A = \pi r^2 for each individual circle
  • Technique: Calculate (2x)2=4x2 (2x)^2 = 4x^2 and (1.5x)2=2.25x2 (1.5x)^2 = 2.25x^2 separately
  • Check: Combine like terms: 4x2π+2.25x2π=6.25x2π 4x^2\pi + 2.25x^2\pi = 6.25x^2\pi

Common Mistakes

Avoid these frequent errors
  • Adding radii before squaring them
    Don't add radii like 2x + 1.5x = 3.5x then square = 12.25x²π! This gives a completely wrong area because you're finding the area of one big circle instead of separate circles. Always square each radius individually, then add the areas.

Practice Quiz

Test your knowledge with interactive questions

Are the expressions the same or not?

\( 3+3+3+3 \)

\( 3\times4 \)

FAQ

Everything you need to know about this question

Why can't I just add all the radii together first?

+

Because area depends on radius squared, not just radius! The area of a circle with radius 5 is 25π 25\pi , but two circles with radii 2 and 3 have total area 4π+9π=13π 4\pi + 9\pi = 13\pi , which is different!

How do I handle variable terms like 2x and constant terms like 3?

+

Square each radius separately using the area formula. Variable radii like 2x 2x give areas with x2 x^2 , while constant radii like 3 give numerical areas. Keep them separate until the final step.

What does it mean to 'combine like terms' at the end?

+

Group terms with the same variables together: all the x2π x^2\pi terms go together (4+2.25+1.44)x2π (4 + 2.25 + 1.44)x^2\pi , and all the constant π \pi terms go together (9+4)π (9 + 4)\pi .

Why do I keep π in my final answer?

+

The π comes from the circle area formula and should stay in your answer unless specifically asked to use a decimal approximation. Leaving π makes your answer exact rather than rounded.

How can I check if my calculation of (1.5x)² is correct?

+

Remember that (1.5x)2=1.52×x2=2.25x2 (1.5x)^2 = 1.5^2 \times x^2 = 2.25x^2 . You can verify: 1.5×1.5=2.25 1.5 \times 1.5 = 2.25

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Algebraic Expressions 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