Cylinders, cones and spheres

At the elementary school of the Corregimiento de Palmitas in the City of Medellín, the teacher wants to make a piñata and in order not to spend a lot of money, she decides to make the party hats in the shape of cones. The teacher needs to make 10 cardboard caps with the following measurement 15 cm radius and 25 cm generatrix. How much cardboard does the teacher need? Formula A = Ab + Al - Ab = π r² - Al = π ra

In the area of civil engineering for road construction, the engineers of the Pacifico 2 road project that is advancing in the municipality of La Pintada, Antioquia, need to build a series of piles that are holes made in the ground in a cylindrical shape that will be the bases that support the bridges. To do this, the engineer in charge needs to know how many cubic meters of concrete he needs to fill a drilled pile with dimensions: 4 m in diameter and 30 m in depth. Find the volume of concrete required for this task. applying the formula v=πr^2 h

What are the elements of the cone?