what are altitudes and angle bisector?

Altitudes are the height of a triangle that meets the ground at a right angle. A angle bisector is when it bisects on a angle in half creating two congruent angles.

what are properties of medians and centroids?

Medians are the line segment a vertex of a triangle to the midpoint of the opposite side. A centroids is the intersection of the three medians in a triangle .

how do we find the volume of cones and pyraminds ?

Cones and pyramids are  A 3-dimensional solid in which the base is a polygon and the sides are triangles which meet in one point called the vertex. A 3-dimensional solid in which the   base is a circle. The side of a cone is formed by straight lines which connect the circular  base  to a vertex. The height is the perpendicular distance from the vertex to the base and meets the  base  in the center of the circle. To find the volume of the pyramids and for cones you need to use the formula of 

 (1/3) b h . 

How do you find the surface area and volume of a sphere ?

A sphere is the set of all points in space equidistant from a given point called a center. To find the surface area you need the formula where S.A=4πr². For the volume you needto use the formula which is 4/3π

 r^{3. This is how you find the surface area and the volume of a sphere.} 

how do we calculate the surface area of a cylinder ?

*We calculate the surface area of a cylinder by L.A+2(B)  .By l which is the length , A is the area and B are the base from the cylinder. That is how we calculate the surface area from a cylinder.

how do we find the surface area and lateral area of pyramids and cones?

*We find the surface area of a pyramid and cones by1/2p.l+ the area of the base. We also find the lateral area of cones and pyramids by 1/2 p.l.