Question

in triangle ABC,AB=AC=10cm.M is the midpoint of BC,BM=6cm. a)find the length of AM. b)What is the area of triangle ABM? c)Find area of triangle ABC.

Answer 1

In the triangle Δabc, ab = ac = 10 cm. (We generally use  ΔABC instead of Δabc)

Here, m is the mid point of bc and bm = 6 cm. So, we have, cm = 6 cm also since m is the mid point of bc

(1) In the triangle Δabm, we have ab = 10 cm, bm = 6 cm. so,

am = √(10^2 - 6^2)

       = 8

ans: length of am is 8 cm.

(2) Area of triangle abm is 8*6/2 = 24 square-cm.(ans.)

(since it is a right triangle)

(3) Area of triangle abc = 2* area of triangle abm

                                       = 2* 24

                                       = 48 square-cm.(ans)