What are the answers of these both questions please answer fast

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16