opengl - WebGL 3d Cylinder and 3d Cone ontop of each other -

i in middle of making webgl program , need create cylinder using triangle strips , cone ontop of using triangle fans create tree simple game type program.

any tips or methods use this, understand how make rectangular prisms @ moment. im beginner in webgl appreciated :)

// block class creates rectangular prism............used steps/obstacles player avoid // constructor function block when created // arguments: vec3 location, floating-point angle (degrees) , vec3 scales function block(location, angle, scales) {     var rs = mult(rotate(angle, [0,0,1]), scalem(scales));     this.trs = mult(translate(location), rs); }  // block's render function // arguments: //   offset - offset of vertices current vertex attribute array //   worldview - current worldview transformation block.prototype.render = function(offset, worldview) {     gl.uniformmatrix4fv(mvloc, false, flatten(mult(worldview, this.trs)));     gl.drawarrays(gl.triangles, offset, block.nv); };  // number of vertices represent cube (nv) block.nv = 36;  //makes vertices block/rectangle block.initmodel = function() {      // 8 raw vertices of cube     var rawverts = [         vec3(-0.5, -0.5,  0.5),         vec3(-0.5,  0.5,  0.5),         vec3( 0.5,  0.5,  0.5),         vec3( 0.5, -0.5,  0.5),         vec3(-0.5, -0.5, -0.5),         vec3(-0.5,  0.5, -0.5),         vec3( 0.5,  0.5, -0.5),         vec3( 0.5, -0.5, -0.5)     ];      // local array in develop 36 vertices     var vertices = [];      // nested function generating vertices each face     function quad(a, b, c, d) {         // if abcd anticlockwise winding on face         // abc , acd anticlockwise windings on triangles         var indices = [a, b, c, a, c, d];          (var = 0; < indices.length; ++i) {             vertices.push(rawverts[indices[i]]);         }     }      //generates cube's faces     function docube() {         // use anticlockwise windings         quad(1, 0, 3, 2);         quad(2, 3, 7, 6);         quad(3, 0, 4, 7);         quad(6, 5, 1, 2);         quad(4, 5, 6, 7);         quad(5, 4, 0, 1);     }      docube();     return vertices; }//end of block.initial model function  //vertices intialised block.vertices = block.initmodel(); //end of block/rectangle class-------------------------------------------