Question

the area of an isoscles triangle is 240cm2and the lengthof each one of the equal side is 26cm find its base​

Answer 1

Answer:

Let a, b, c are sides of isoscles triangle.

As a=b=26cm

c is base of triangle.

As area=1/2*ab sinC.(C is let say angle between a and b.

or, 240=1/2*26*26*sinC

or, sinC=0.71

or,cosC=root(1-sin^2C)

or,CosC=0.7

From trigonometry formula,

sin(C/2)=root((1-cosC)/2)

=root(0.15)

=0.39

Length of base=2*26*sin(C/2)

=52*0.39

=20.28cm