abc is an isosceles triangle in which ab=ac=5cm and BC =6cm.calculate \am\where m is the midpoint of BC

If you make your sketch, you should realize that you have

two congruent right-angled triangles with base 3, and hypotenuse 5.
You should recognize the basic 3-4-5 right angled triangle, since
3^2 + 4^2 = 5^2
so AM = 4

To find the length of \am\, we can use the Pythagorean theorem.

First, let's draw a diagram of the triangle ABC.

A
/ \
/ \
/ \
/ \ m
/ \
B-----------C

Since ABC is an isosceles triangle, we know that the base angles at B and C are equal. Let's call them \angle BAC and \angle CAB.

Since AB = AC, we can say that \angle BAC = \angle CAB.

Since ABC is an isosceles triangle, we can also say that BM = CM (M is the midpoint of BC).

Now, let's use the Pythagorean theorem to find the length of \am\.

In triangle ABM, we have:

AB^2 = AM^2 + BM^2

Substituting the known values, we have:

5^2 = AM^2 + (BC/2)^2

Simplifying the equation:

25 = AM^2 + (6/2)^2
25 = AM^2 + 9
AM^2 = 25 - 9
AM^2 = 16

Taking the square root of both sides, we get:

AM = 4 cm

Therefore, the length of \am\ is 4 cm.