Question

15. In an equilateral triangle ABC, D is a point on side BC such that BD-3 BC Prove that
9 AD2=7 AB?​

Answer 1

answer ⬇️⬇️


( we draw a line AP that is perpendicular to BC , AP being the altitude acts also as the median in the given triangle as ABC is equilateral )
( properties used ==> (a+b)^2 = a^2 + b^2 + 2ab
Pythagorus property )
( Also keep in mind that the sides are all equal , that is AB=BC=BD)



( i havent included the LCM taking and then subtracting in the subtraction of fractions down below)

Answer 2

Answer:

Check your answer please