First we have to find the diagonal of the card. We do this by using the Pythagoras theorem: A^2 = b^2 + c^2 = 6^2 + 4^2 =36 + 16 = 52 A^2= 52 Sqrt A^2 = sqrt 52 A = 7.2 Since the envelopes diagonal is 7.2 inches and the card’s diagonal is 8 inches and 7.2<8. Your answer is c)