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The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.

Acollection of nickels and quarters is worth $2.85. there are 3 more nickels than quarters.how many nickels and quarters are there?

Which is the standard form for this number? (2 x 10) + (5 x 1) + (8 x 1 10,000 )