Surface area of a cone

Areas related to cone are introduced with geogebra sketch.

Objectives
Understand surface area

To calculate surface area of a cone

Estimated Time
40 minutes.

Prerequisites/Instructions, prior preparations, if any
Basics about cone, circle and pythogoras theorm should have been covered.

Materials/ Resources needed
Digital: Laptop, geogebra file, projector and a pointer.

Geogebra file: Sector of a Cone,  Surface area of a cone

Process (How to do the activity)
The teacher after initial discussion on a cone and its properties can project the geogebra file and enable the understanding of derivation of formulae for surface area of a cone.
 * Developmental Questions:
 * 1) What is a solid shape ?
 * 2) Define a cone ?
 * 3) Give some examples of conical figures.
 * 4) Name the parts of a cone.
 * 5) What shape is its base.
 * 6) After disection can you identify the shapes it is made of ?
 * 7) Differentiate lateral surface area and total surface area.
 * 8) What is the formula to find the area of a circle ?
 * 9) Whatis the circumference of a circle ?
 * 10) Differentiate between the slant height and vertical height of a cone.
 * 11) How do we proceed to find the L.S.A. of the cone.
 * 12) How do we find the total surface area of the cone.
 * Evaluation:
 * 1) What part of a circle is the lateral surface of a cone ?
 * Question Corner:
 * 1) What would be the formula to find the surface area of an ice-cream cone.
 * 2) What is the frustum of a cone.