In an isosceles triangle ABC of area 42 cm^2, AB=AC. If the base BC=(4x+5) cm and the altitude AD = x cm the find the equal sides of the triangle, correct to two decimal places.

• 11.23cm with the base length at 21cm
  
• 11 years agoHelpfull: Yes(0) No(0)
• equal sides of a triangle=11.23
  let equal side of a triangle be a
  area of a isosceles triangle=(b*h)/2
  ((4x+5)(x))/2=42
  4x^2+5x-84=0
  by solving the eq x=4.
  so base=21 and altitude=4
  altitude of a isosceles triangle(h)=sqrt(a^2-(base^2/4))
  4=sqrt(a^2-(21^2/4))
  by solving a=11.23
• 11 years agoHelpfull: Yes(0) No(0)