1.make a iron frame in the shape of t.v dish                                                          2.cut the acrylic mirror sheets into 8 or 12 pieces in the shape of isosceles triangle with a height equal to the radius of your dish antenna.                                          3.the bases of 8 or 12 triangles together make the circumference of the dish.          4.stick the triangle mirrors to the dish.                                                                  5.face the dish towards the sun.Find the focal point and place a vessel at that point.                                                                                                        will get heated.In this way we will make a solar cooker    
Solar cooker is just like a T.V dish 
a concave mirror converges parallel sun rays at focus
we have to prepare a concave mirror and focus should be known
by keeping any thing on focus we can heat that thing
therefore solar cooker is prepared