Question

A teacher gave her students a paper square. The first student cut this square into two shapes, using one straight cut not through any of the paper’s corners. The second student cut one of the resulting shapes, using one straight cut not through any of that shape’s corners, and so on. After 10 students had made their cuts, there were eleven shapes, including seven triangles, two quadrilaterals, and a pentagon. How many sides were in the remaining shape?

Answer 1

$total \: number \: of \: sides \\ =( 7 \times 3) + (2 \times 4) + (1 \times 5) \\ = 21 + 8 + 5 \\ = 34$