MHB [ASK] Find the ratio of the area of triangle BCH and triangle EHD

AI Thread Summary
The discussion focuses on finding the ratio of the areas of triangles BCH and EHD within a rhombus ABCD, where angles A and C are both 45°. It is established that triangles BCH and EHD are similar due to their corresponding angles. The area of triangle BCH is calculated using its base and height, while the area of triangle EHD is derived from its corresponding dimensions. The ratio of the areas simplifies to 1:2, indicating that the area of triangle BCH is half that of triangle EHD. This conclusion is reached through geometric relationships and properties of similar triangles.
Monoxdifly
MHB
Messages
288
Reaction score
0
A parallelogram ABCD has angle A = angle C = 45°. Circle K with the center C intercept the parallelogram through B and D. AD is extended so that it intercepts the circle at E and BE intercepts CD at H. The ratio of the area of triangle BCH and triangle EHD is ...

Here I got that triangle BCH and triangle EHD is similar with angle BCH = angle HDE = 45°, angle CHB = angle DHE = 112.5°, and angle CBH = angle DEH = 22.5°. The area of triangle BCH is ½ × CH × h, where h is the parallelogram's height. The area of triangle EHD is ½ × (r - CH) × r. I stuck at the ratio is (CH × h) : ((r - CH) × r). How do I simplify that? Problem is, I don't know CD's length, so I can't approximate the ratio between CH and DH.
 
Mathematics news on Phys.org
A parallelogram ABCD has angle A = angle C = 45°. Circle K with the center C intercept the parallelogram through B and D. AD is extended so that it intercepts the circle at E and BE intercepts CD at H. The ratio of the area of triangle BCH and triangle EHD is ...

Note parallelogram ABCD is a rhombus with side length $r$ ...

(area of BCH)/(area of EHD) = $\dfrac{r^2}{(r\sqrt{2})^2} = \dfrac{1}{2}$
 
How did you get area of BCH and area of EHD?
 
Monoxdifly said:
How did you get area of BCH and area of EHD?

I didn't get the areas ... I determined the ratio of their respective areas.

From the diagram, let triangle BCH have base r with a perpendicular height h. Since triangle EHD is similar, its corresponding base is r√2 with corresponding height h√2.

$\dfrac{\text{area of BCH}}{\text{area of EHD}} = \dfrac{\frac{1}{2}r \cdot h}{\frac{1}{2} r\sqrt{2} \cdot h\sqrt{2}}$

now ... simplify the right side of the above equation.
 
1 : 2
 
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
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...
Back
Top