MHB Find the scale factor of triangle ABC to triangle DEF

AI Thread Summary
Triangles ABC and DEF are similar, with triangle ABC having a perimeter of 16 cm and triangle DEF having sides of 6 cm, 8 cm, and 10 cm, totaling a perimeter of 24 cm. The scale factor of triangle ABC to triangle DEF is determined to be 2/3 based on the perimeter ratio of 16:24. There is a distinction between the dilation scale factor, which is 3/2, and the scale ratio, which is less than 1 since triangle ABC is smaller. The confusion arises from the terminology used, as the question specifically asks for the "scale factor." Therefore, the correct scale factor from triangle ABC to triangle DEF is 2/3, not 3/2.
masters1
Triangles ABC and DEF are similar.

Triangle ABC has a perimeter of 16cm.

Triangle DEF has side of 6cm, 8cm and 10cm.

What is the scale factor of triangle ABC to triangle DEF?

A. 1/2
B. 1/3
C. 2/3
D. 3/2
E. 2/1

I concluded the answer is D. Am I correct?
 
Mathematics news on Phys.org
What is the scale factor of triangle ABC to triangle DEF?

perimeter of ABC : perimeter of DEF = 16:24 = 2:3
 
There is a difference between the "scale factor of triangle ABC to triangle DEF" and the "scale factor of triangle DEF to triangle ABC". You found the wrong one! Since ABC is smaller than DEF, the scale factor is less than 1.
 
Then, is this textbook example incorrect?
 

Attachments

  • what-is-a-scale-factor-multiplier-similar-triangles.png
    what-is-a-scale-factor-multiplier-similar-triangles.png
    9.1 KB · Views: 131
The dilation scale factor, which is a transformation, of triangle ABC to triangle DEF is 3/2

The scale ratio, like a map's scale, of triangle ABC to triangle DEF is 2/3

Sorry for the confusion.
 
skeeter said:
The dilation scale factor, which is a transformation, of triangle ABC to triangle DEF is 3/2

The scale ratio, like a map's scale, of triangle ABC to triangle DEF is 2/3

Sorry for the confusion.

So, the question asked about "scale factor", not ratio of any kind. Is the answer, in fact, "D", which is 3/2?
 
Thread 'Video on imaginary numbers and some queries'
Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Thread 'Unit Circle Double Angle Derivations'
Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...

Similar threads

Back
Top