MathDB
2016 MBMT Geometry Round - Montgomery Blair Math Tournament

Source:

October 14, 2023
geometryMBMT

Problem Statement

[hide=E stands for Euclid, L stands for Lobachevsky]they had two problem sets under those two names
E1. What is the perimeter of a rectangle if its area is 2424 and one side length is 66?
E2. John moves 3 miles south, then 22 miles west, then 77 miles north, and then 55 miles east. What is the length of the shortest path, in miles, from John's current position to his original position?
E3. An equilateral triangle ABCABC is drawn with side length 22. The midpoints of sides ABAB, BCBC, and CACA are constructed, and are connected to form a triangle. What is the perimeter of the newly formed triangle?
E4. Let triangle ABCABC have sides AB=74AB = 74 and AC=5AC = 5. What is the sum of all possible integral side lengths of BC?
E5. What is the area of quadrilateral ABCDABCD on the coordinate plane with A(1,0)A(1, 0), B(0,1)B(0, 1), C(1,3)C(1, 3), and D(5,2)D(5, 2)?
E6 / L1. Let ABCDABCD be a square with side length 3030. A circle centered at the center of ABCDABCD with diameter 3434 is drawn. Let EE and FF be the points at which the circle intersects side ABAB. What is EFEF?
E7 / L2. What is the area of the quadrilateral bounded by 2x+3y=6|2x| + |3y| = 6?
E8. A circle OO with radius 22 has a regular hexagon inscribed in it. Upon the sides of the hexagon, equilateral triangles of side length 22 are erected outwards. Find the area of the union of these triangles and circle OO.
L3. Right triangle ABCABC has hypotenuse ABAB. Altitude CDCD divides ABAB into segments ADAD and DBDB, with AD=20AD = 20 and DB=16DB = 16. What is the area of triangle ABCABC?
L4. Circle OO has chord ABAB. Extend ABAB past BB to a point CC. A ray from CC is drawn, and this ray intersects circle OO. Let point DD be the point of intersection of the ray and the circle that is closest to point CC. Given AB=20AB = 20, BC=16BC = 16, and OA=2016OA = \frac{201}{6} , find the longest possible length of CDCD.
L5. Consider a circular cone with vertex AA. The cone's height is 44 and the radius of its base is 33. Inscribe a sphere inside the cone. Find the ratio of the volume of the cone to the volume of the sphere.
L6. A disk of radius 12\frac12 is randomly placed on the coordinate plane. What is the probability that it contains a lattice point (point with integer coordinates)?
L7. Let ABCABC be an equilateral triangle of side length 22. Let DD be the midpoint of BCBC, and let PP be a variable point on ACAC. By moving PP along ACAC, what is the minimum perimeter of triangle BDPBDP?
L8. Let ABCDABCD be a rectangle with AB=8AB = 8 and BC=9BC = 9. Let DEFGDEFG be a rhombus, where GG is on line BCBC and AA is on line EFEF. If mEFG=30o,whatism\angle EFG = 30^o, what is DE$?
PS. You should use hide for answers. Collected [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here.