1.
clip-path: polygon(0 0 , 100% 0,100% 90%, 55% 90%,50% 100%, 45% 90%,0 90% );
-webkit-clip-path: polygon(0 0 , 100% 0,100% 90%, 55% 90%,50% 100%, 45% 90%,0 90% );
2.
clip-path: polygon(20% 0 , 80% 0,100% 50%, 80% 100%,20% 100%, 0 50% );
-webkit-clip-path: polygon(20% 0 , 80% 0,100% 50%, 80% 100%,20% 100%, 0 50% );