Question

in a quadrilateral ABCD angle b is equal to 90 degree and A D square is equals to a square + b square + c square prove that angle ACD is equal to 90 degree​

Answer 1

Step-by-step explanation:

As ∠ABC=90

So applying Pythagoras theorem in △ABC

AB^2 +BC^2 =AC^2 ........ (1)

Given: AD^2 =AB^2+BC^2+CD^2........ (2)

Substituting (1) in (2)

AD^2 =AC^2+CD^2

In △ACD , applying converse of Pythagoras theorem which states

that if the square of the length of the longest side of a triangle is equal to the sum of the squares of the other two sides, then the triangle is a right triangle.

Hence ∠ACD=90