What are the two procedures for ratifying and amending the us constitution? (select all that apply.)

The first procedure for ratifying and amending the US Constitution involves approval by two-thirds of the House and Senate after which the proposal is sent to the states for a vote. Then, three-fourths of the states must affirm the proposed Amendment. Alternatively, a Constitutional Convention can be called by two-thirds of the legislatures of the States. The Convention can propose  amendments which must be approved by three-fourths of the states before amending the Constitution.