House Rotation

4) Write an OpenGL Program to create a house like figure and rotate it about  a given fixed point using OpenGL functions.

#include<stdio.h>
#include<math.h>
#include<GL/glut.h>
GLfloat house[2][9]={{100.0,100.0,175.0,250.0,250.0,150.0,150.0,200.0,200.0},        {100.0,300.0,400.0,300.0,100.0,100.0,150.0,150.0,100.0}};
GLfloat theta;
GLfloat h=100.0;
GLfloat k=100.0;
void drawhouse()
{
    glColor3f(1.0,0.0,0.0);
    glBegin(GL_LINE_LOOP);
    glVertex2f(house[0][0],house[1][0]);
    glVertex2f(house[0][1],house[1][1]);
    glVertex2f(house[0][3],house[1][3]);
    glVertex2f(house[0][4],house[1][4]);
    glEnd();
    glColor3f(1.0,0.0,1.0);
    glBegin(GL_LINE_LOOP);
    glVertex2f(house[0][5],house[1][5]);
    glVertex2f(house[0][6],house[1][6]);
    glVertex2f(house[0][7],house[1][7]);
    glVertex2f(house[0][8],house[1][8]);
    glEnd();
    glColor3f(1.0,0.0,0.0);
    glBegin(GL_LINE_LOOP);
    glVertex2f(house[0][1],house[1][1]);
    glVertex2f(house[0][2],house[1][2]);
    glVertex2f(house[0][3],house[1][3]);
    glEnd();
}
void display()
{
    int i;
    GLfloat m[16],p,q;
    p=-h*(cos(theta)-1)+k*(sin(theta));
    q=-k*(cos(theta)-1)-h*(sin(theta));
    for(i=0;i<15;i++)
        m[i]=0.0;
    m[0]=cos(theta);
    m[1]=sin(theta);
    m[4]=-sin(theta);
    m[5]=cos(theta);
    m[12]=p;
    m[13]=q;
    m[10]=1;
    m[15]=1;
    glMatrixMode(GL_MODELVIEW);
    glClear(GL_COLOR_BUFFER_BIT);
    drawhouse();
    glPushMatrix();
    glMultMatrixf(m);
    drawhouse();
    glPopMatrix();
    glFlush();
}
void myinit()
{
    glClearColor(1.0,1.0,1.0,1.0);
    glColor3f(1.0,1.0,0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0,499.0,0.0,499.0);
    glMatrixMode(GL_MODELVIEW);
}
int main(int argc,char **argv)
{

    printf("enter the rotation angle\n");
    scanf("%f",&theta);
    theta=theta*3.141/180;
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(0,0);
    glutCreateWindow("rotated house");
    glutDisplayFunc(display);
    myinit();
    glutMainLoop();
    return 0;
}
Input:
enter  the rotation angle
-30