geometry

  1. A

    Couple of elementary geometry problems

    1. In triangle ABC AB=BC=4, angle ABC=30 degrees. On the outside of sides AB and BC, equilateral triangles ABD and BCF are constructed. Lines AF and CD intersect in point O. Find angles of the triangle AOC and distance between lines AC and DF. 2. Bisectors of angles A and B of parallelogram...
  2. A

    Geometry Puzzle - Need help.

    Hi everyone, I've just joined this forum and I'd like to ask its members for their assistance. I found this underlying geometry between four fixed points (Buildings). As you can see, the diameters of the two circles are related to the Golden Ratio. I would like to ask the mathematicians...
  3. J

    Geometry Construction Set

    Hello, You may be interested in my Geometry Construction Set: https://github.com/jfbouzereau/geom Best regards JFB
  4. tahirimanov19

    Geometry Problem Series, Question 3:

    Pentagon $ABCDE$ is inscribed in a circle. $AB \parallel EC$, $AE \parallel BD$. $AD \cap EC \equiv G$, $BD \cap EC \equiv F$ and $AC \cap BD \equiv H$. Prove that the area of $AGFH$ is equal to the sum of the areas of $DEG$ and $BCH$. --------
  5. tahirimanov19

    Geometry Problem Series, Question 2:

    $T$ is the middle point of the segment $AB$ of the convex quadrilateral $ABCD$. The circle $\omega$, through points $C,D,T$, is tangent to $AB$. $K$ and $L$ are the intersection points of $AD$ and $BC$ respectively with $\omega$. $M$ and $N$ are the intersection points of $AC$ and $BD$...
  6. tahirimanov19

    Geometry Problem Series, Question 1:

    A circle circumscribed to the triangle $ABC$. $D$ is a point on the circumcircle. Prove that symmetries of the point D according to the edges of the triangle are collinear.
  7. MATHEMATICIAN

    logical help

    I want to select N random points of intersection without repetition. 1. any intersection point 2. only along perimeter The gap between the lined horizontally and vertically are same 'D' The number of lines may differ from that of the picture, depending on values of L1, L2, W1, W2 and D
  8. Split39

    What are some good Geometry Books to read ?

    I am looking for a beginner friendly book that covers basic geometry and trigonometry I was able to clear a lot of basic doubt with a book like this , Homework Helpers Basic Math And Pre Algebra, Denise Szecsei Ph.D I also have this book with me , Geometry and Trigonometry for...
  9. O

    Find the smallest expression value

    About a convex hexagon ABCDEF it is known that AB = BC, CD = DE, EF = FA. Find the smallest value of the expression: BC / BE + DE / DA + FA / FC
  10. R

    Geometry Similar Polygons

    I need help with solving these questions. I’m having trouble with setting up the proportion and finding the scale factor. For #2a, would the proportion be 10/15 and 15/20?
  11. A

    Why Plane in Geometry looks like "Triangle Shape"?

    Why Plane in Geometry looks like "Triangle Shape"? it's confuses me when saying about "Triangle"!
  12. Abisha100

    Non-Euclidean Geometry (NEG): New Outlook(?)

    Non-Euclidean Geometry (NEG) is a special branch of geometry involving postulates about parallel lines or intersecting lines that are 'alternatives' to standard Euclidean Geometry (EG) which is why we see 'irregular' or 'multi-definitional' shapes in NEG analysis/exploration. NEG inquiries...
  13. ProofOfALifetime

    Geometry diagrams

    Dear MyMathForum friends, I was wondering what you use to create diagrams when submitting geometry solutions. I know $\LaTeX$ but I don't know how to create diagrams. For example, I see these complicated geometry diagrams people submit to Mathematics Magazine, but I'm not sure how to create...
  14. H

    Basic geometry info (transversals and angle relationships)

    Found these vids on youtube. hopefully they help somebody going thru this https://www.youtube.com/watch?v=CTPSs6P-8kA&list=PLanVcrvkL5E_IhudxOX-oqpLBMABTq8QX
  15. J

    Geometry joke.

    Hello, So, I made a math joke. I want an opinion on it. I think it needs work, what do you guys think? Two people are texting each other. Person 1: "I made Pi today!" Person 2: "Can I have the recipe?" Person 1: "Here: (180*10^n)*2COS((180-(360/(360*10^n)))/2) is equal to...
  16. E

    Quick Geometry and Trigonometry Questions

    1. If a right triangle has equal legs, the hypotenuse divided by a leg is the square root of 2. If a right triangle has unequal legs, is it always true that the hypotenuse divided by the longer leg is less than the square root of 2 and the hypotenuse divided by the shorter leg is greater than...
  17. I

    Probability involving geometry

    What is the probability such that a rectangle is a square ?
  18. T

    Find duplicate Geometry with Linear Transform

    Hey, I'm working on an algorithm that finds duplicate Geometry. Here's what I do: I'll take a mesh, get all it's vertices and find the average of them: x = average(a, b, c, d, e, f) then I'll get the distances of the average to the vertices: ad = dist(x, a) bd = dist(x, b) cd =...
  19. H

    A geometry time question

    If a rescue craft is launched from Miami and can travel with a maximum speed of 35 knots, how long should it take to reach the crash site? Note: 1 knot = 1.852 km/hr. The approximate distance in this region for latitude of 1° = 111 km and longitude 1° = 100 km. Let's suppose the coordinates...
  20. H

    Geometry math problem

    A plane has crashed equidistant from M (-80,26) and S (-66,18) and is on altitude from M. Locate where the plane has crashed co-ordinates in latitude and longitude are M(-80,26) H(-65,32) S(-66,18) Note - it's a triangle.