1998 CEMC Gauss (Grade 7) Problems/Problem 17

Problem

Claire takes a square piece of paper and folds it in half four times without unfolding, making an isosceles right triangle each time. After unfolding the paper to form a square again, the creases on the paper would look like:

(see attached pdf for diagrams)

$\text{(A)}\  \qquad \text{(B)}\  \qquad \text{(C)}\  \qquad \text{(D)}\  \qquad \text{(E)}$

Solution

For each fold, you are folding along the diagonal of the shape to form an isosceles triangle. The finished result should look like $\boxed{\text{(C)}}.$