MHB Solve Quadratic Equation: Ratio of Two Cones' Radii

  • Thread starter Thread starter Monoxdifly
  • Start date Start date
Click For Summary
Azis is constructing two cones with specific relationships between their dimensions. The surface area of the first cone is twice that of the second, and its side length is also double. The equations derived from these relationships lead to a ratio of the radii, suggesting that r1 is four times r2. However, the base area must also be considered to finalize the ratio. The discussion emphasizes the importance of quadratic equations in solving for the radius ratio of the cones.
Monoxdifly
MHB
Messages
288
Reaction score
0
Azis wants to make two cones using cartons. The surface area of the first cone is twice the second. The side length of the first cone is also twice the second. Determine the ratio of those cones' radius!

s1 = 2s2
L1 = 2L2
πr1(r1 + s1) = 2πr2(r2 + s2)
r1(r1 + 2s2) = 2r2(r2 + s2)

I was stuck with quadratic equations...
 
Mathematics news on Phys.org
Monoxdifly said:
Azis wants to make two cones using cartons. The surface area of the first cone is twice the second. The side length of the first cone is also twice the second. Determine the ratio of those cones' radius!

s1 = 2s2
L1 = 2L2
πr1(r1 + s1) = 2πr2(r2 + s2)
r1(r1 + 2s2) = 2r2(r2 + s2)

I was stuck with quadratic equations...
$A_1 = 2A_2 \implies \pi r_1 \cdot L_1 = 2\pi r_2 \cdot L_2 \implies \pi r_1 \cdot L_1 = 2\pi r_2 \cdot 2L_1 \implies \dfrac{r_1}{r_2} = 4$
 
But we must take into account the base area...
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

Similar threads

Replies
1
Views
987
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 7 ·
Replies
7
Views
7K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
15K
  • · Replies 5 ·
Replies
5
Views
7K
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
11K
Replies
10
Views
7K