Question

ABC is a triangle ,D is the midpoint of BC,and AD is perpendicular to BC.Prove that area of triangle ABC = 1/2 multiplied by AD multiplied by BC

Answer 1

first ,area of triange abd and tri acd
                bd=cd  ......given
                 ab=ac........given
                 angle bda =angle cda.........given
          hence, triangle abd= triangle acd 
                 therefor  tri abc = 1/2 ad