 Hello and welcome to the session. In this session we will discuss the question which says that find the vertical surface area of a regular pyramid with a square base if each edge of the base measures 16 centimeters, the sand height of a site is 17 centimeters and altitude is 15 centimeters using that as well as formula. Now before starting the solution of this question we should know some results. First is the surface area of any polyhedron is the sum of the areas of its lateral faces and the faces and secondly what is the two-dimensional representation of a three-dimensional figure. Now these results will welcome you as a key idea for solving the given question. Now let us start with the solution of the given question. Now in this question we have to find the total surface area of a regular pyramid with square base if each edge of the base measures 16 centimeters the sand height of the site measures 17 centimeters and altitude is 15 centimeters using net as well as formula. So given a regular pyramid with edge of the base as equal to 16 centimeters, sand height of a site is equal to 17 centimeters, altitude is equal to 15 centimeters. Now to find the area of the pyramid we should find the area of all four lateral faces and the base. To do this we shall find the area using net. Now from the key idea we know that net is the two-dimensional representation of a three-dimensional figure. So where we will draw the net for this pyramid. Now here we have drawn the net of this given pyramid. First of all we have taken the square base ABCD and to each edge of the square base there is a lateral face attached which is a triangle. Now first of all we will find the area of the base. Now as the base is square with site 16 centimeters. So the area of the base will be equal to site into site which is equal to 16 centimeters into 16 centimeters which is equal to centimeter square. Now let this be equation number one. Now next we will find the area of the four lateral faces. That is the area of the four triangles. Now as the dimensions of these four triangles are same. So the area is also same. That is these four triangles have equal area. Here each triangle has the base is equal to 16 centimeters and slant height is the height of each triangle. That is height of each triangle is 17 centimeters. So the area of triangle EAB is equal to area of triangle. ECB is equal to area of triangle. PTA is equal to half into base into height which is equal to half into now base of each triangle is 16 centimeters and height of each triangle is 17 centimeters. Now 2 into 8 is 16. So this is equal to 136 centimeters square. Now let this be equation number two. Now from the tier area we know that surface area of any triangle is the sum of the areas of its lateral faces and the bases. Now the total surface area of the pyramid is the areas plus area. Now from equation number one we have the area of the base which is equal to 256 centimeters square which is equation number two which are the lateral faces which is 136 centimeters square lateral faces which are equal. So the sum of the areas of the lateral faces plus given pyramid will be equal to meter square. The total surface area of the pyramid will be equal to into 136 centimeters square centimeters square 534 centimeters square plus 25 which is equal to centimeters square. So by using the net we have got the total surface area of the pyramid which is equal to 800 centimeters square. Now let us find the area of the pyramid that is the total surface area of the pyramid by using the formula. Let us find the parameter of the base that is the parameter of the square base which is equal to 20 meters. So this is equal to 4 into 16 centimeters which is equal to centimeters. So the parameter is equal to now the area of the base is equal to side into side which is equal to 16 centimeters therefore area that is B is equal to So the total surface area into B into S the area of the base is equal to 64 centimeters B is equal to 2 into 64 into 17 plus now 2 into 32 is 64 2 into 17 plus 244 plus 256 is equal to 800 centimeters square the pyramid is equal to 800 centimeters square this area of the pyramid by using net as well as the formula. And this is the solution of the given question. That's all for this session. Hope you all have enjoyed this session.