Tagged Questions
2
votes
4answers
43 views
How can I solve this Laws of Sines problem?
This is a homework question that was set by my teacher, but it's to see the topic our class should go over in revision, etc.
I have calculated $AB$ to be 5.26m for part (a). I simply used the law ...
0
votes
0answers
23 views
find area of Triangle ABF
In the figure given below , rectangle CDEF with perimeter 32 has the maximum area. find area of Triangle ABF
So , i had following try.
P = 2.W+2.H where ...
-2
votes
2answers
46 views
Find area of triangle ABC
BD Perpendicular AC , AB =BC=a
Find the area of triangle ABC
I have tried Googling , I used formula 1/2 (base X Height) . Used Pythagorean theorem. Anyone can suggest me solution.
2
votes
4answers
64 views
Length of Triangle BCD
Hey, well I'm doing some higher level revision and I'm stuck...
In the diagram triangle BCD is mathematically similar to triangle ACE.
So what is the length of BD? How do you work it out?
1
vote
0answers
35 views
Proving that the circumcenter is the centroid
Given a triangle and its centroid, we know that the 3 line segments between the centroid and each of the vertices of the triangle divide the triangle into three smaller triangles. Prove that the ...
2
votes
2answers
32 views
Congruent Triangles
Triangle ABC and Triangle DBC are two isosceles triangles on the same base BC and vertices A and D are on the same side of BC.If AD is extended to intersect BC at P,show that
(a)Triangle ABD ≈ ...
0
votes
2answers
60 views
A question on Trigonometry (bisector)
If two bisector of a triangular is equal, then it is Isosceles triangular.
2
votes
4answers
111 views
Circle/Triangle math problem
The question asks to find angles $\angle X$ and $\angle Y$, however I don't know how to do this without assuming that lines $\overline {GO}$ and $\overline{OJ}$ are parallel. The only angle given is ...
0
votes
1answer
52 views
How to determine a Triangle vertices by its coordinates?
I have to solve this problem, yet I'm not sure what is asked.
Given a triangle whose vertices are defined by its coordinates. Determine where is the point O with the given coordinates - inside or ...
2
votes
3answers
1k views
Given the base and angles of an isosceles triangle, how to find length of the two sides?
I can't seem to find a textbook solution to this. It is always assumed that the length of the sides is know.
Isolceles triangle
So the base $a$ is known. The bottom angles where $\alpha$ and the ...
1
vote
3answers
80 views
Does every set of any three vertices of a cube determine a right triangle?
I recently came across this in my textbook:
Any three vertices of a cube determine a right triangle. Is this a true statment?
My initial thought was that is was, but the answers say otherwise. ...
0
votes
3answers
332 views
Triangle Inside Circle
If the radius of the circle is equal to the length of the chord $AB$, what is the value of $x$?
How would I solve this problem ?
1
vote
1answer
477 views
Pythagorean theorem
We can make a square into four equal squares. Fine, if we want to make into five.. Then there is a problem. Please discuss, How to make five squares from a single square by using a Pythagorean ...
4
votes
1answer
468 views
Whats the sum of the length of all the sides of a triangle?
You are given triangles with integer sides and one angle fixed at 120 degrees. If the length of the longest side is 28 and product of the remaining to sides is 240, what is the sum of all sides of the ...
2
votes
1answer
158 views
In center-excenter configuration in a right angled triangle
My question is:
Given triangle ABC , where angle C=90 degrees.
Prove that the set { s , s-a , s-b , s-c } is identical to { r , r1 , r2 , r3 }.
*s=semiperimeter , r1,r2,r3 are the ex-radii.
Any ...
2
votes
2answers
113 views
Triangle related question
My question is:
In Triangle ABC , let AE be the angle bisector of angle A. If 1/AE = 1/AC + 1/AB , then prove that angle A = 120 degrees.
What i tried: I extended side AB and took a point M on it ...
0
votes
1answer
26 views
a question on “basic triangle at q”
Could someonehelp me to understand these sentences:
A “basic triangle at $q$” will mean a triangle which has the sides adjacent to the vertex $q$ of equal length and an angle at $q$ of measure ...
9
votes
3answers
819 views
how to prove DEF is an equilateral triangle?
ABC is an equilateral triangle，and AD = BE = CF，Prove DEF is an equilateral triangle.
0
votes
1answer
85 views
A question on triangles
The radii $r_1,r_2,r_3$ of ex-scribed circles of the triangle $ABC$ are in harmonic progression. If the area of the triangle is $24$ sq.cm and its perimeter is $24$ cm, then what is the length of the ...
2
votes
1answer
250 views
Maximum triangle area
I have a small problem. Consider I have a triangle. Which maximum area can it cover if two of his medians are 3 and 8?
I think I'll need to use derivative here, but firstly I need to find a function ...
1
vote
3answers
162 views
Systems of equations finding right triangles
I need help setting up the equation for the question, "Find all right triangles for which the perimeter is $24$ units and the area is $24$ square units."
I know that the area is $A = \frac12 b h$ ...
0
votes
1answer
71 views
Quadratic Equation related question.
So here's the question :
The hypotenuse of a right triangle is $3 \sqrt 5$ cm. If the smaller side is tripled & the larger side is doubled, the new hypotenuse will be $15$ cm. Find the length of ...
0
votes
1answer
238 views
Computing circumcenter of triangle in 2D with MATLAB
I'm writing a finite volume program over a 2D triangular mesh, and at one point I need to calculate the circumcenters of the triangles. The equation given in class and that on Wikipedia give different ...
0
votes
0answers
164 views
How to find the last coordinate of an isosceles triangle
I'm having some trouble trying to find out how to find the final coordinate on an isosceles triangle.
Here's a list of information that I have:
The length of the two equal sides (A and B)
The angle ...
4
votes
2answers
280 views
Proving $\cot(A)\cot(B)+\cot(B)\cot(C)+\cot(C)\cot(A)=1$
I was stumped by another past-year question:
In $\triangle ABC$, prove that $$\cot(A)\cot(B)+\cot(B)\cot(C)+\cot(C)\cot(A)=1.$$
Here's what I have done so far: I tried to replace $C$, using ...
