Two circles of area π and 9π respectively are contained in a parallelogram. What’s its area?
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Velocipede II
Category: Intermediate
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The pyramid perspective
Two congruent pyramids placed at different distances from the observer appear as equilateral triangles in a square frame. If the closest one is at 100 meter, how far is the distant pyramid?
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The Pacman principle
In a circle, two congruent chords are connected in a point. A line segment is drawn through the circle center as shown, forming two angles. What is the proportion α : β?
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The blue diamond
Two isosceles triangles are placed as shown. What is the proportion of the line segments a and b?
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The inner wheel
A wheel is placed inside another that has exactly twice its radius. If the inner wheel rolls around once without slipping, how many revolutions has it completed?
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The blockhat
Four congruent rectangles are placed in a hat-shaped configuration. What’s the angle between the lines connecting the opposite corners?
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The corner pocket
A snooker player wants to corner a ball starting from a point on one side and bouncing two times from the opposite sides. Given the dimensions of the table in the figure, what’s the length of the track the snooker ball travels?
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Balancing balls
Two touching circles are placed on top of a right triangle. What’s the angle between the chords connecting the tangency points?
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The marble box
Two marbles of sizes π and 4π are enclosed in a rectangular box. What is the total area of the box?
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The triangle tango
An isosceles triangle is attached to another triangle with a 60-degree angle as shown. Their opposite vertices are connected by a line segment of length 2. What is the area of the quadrilateral?