Which set of sides will make a triangle ?
A. 5cm ,2cm , 3cm
B. 10cm , 3cm ,4cm
C. 1cm, 3cm ,1cm
d. 10cm , 5cm , 9cm
QUICK PLS

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

Three baby penguins and their father were sitting on an iceberg 0.50.50, point, 5 meters above the surface of the water. the father dove down 4.74.74, point, 7 meters from the iceberg into the water to catch dinner for his kids. what is the father penguin's position relative to the surface of the water?

Which one is the correct answer, and why?