A symmetric tree has decorative lines of equal slope, and of lengths 11 and 13. What is the area ratio of green to red to brown?
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Decorating the tree
Category: Beginner
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The brick pile
Three congruent rectangles inscribed in a triangle. What fraction is brown?
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Inside the box
Two squares inside a square share a vertex. What’s the angle α?
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Folding a pentagon
One side of a regular pentagon is folded back and forth as shown. Are the six red line segments congruent?
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Lemon slice II
A semicircle inscribed in a quarter circle. What fraction is yellow?
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The double iglo
Two semicircles with their centres. What’s the angle α?
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The propeller
The blue square blades are twice as long as the red triangle sides. What is the ratio of red to yellow areas?
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The two-state solution
Two congruent squares share a vertex. What fraction is yellow?
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Wild floor tile
What is the ratio of areas, purple/green, when the orange octagon is regular (all angles equal)?
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Mix master
What is the sum of the angles at the blue vertices of this 11-gon?