Question

if cos²A+cos²C=sin²B then it is which type of triangle a)equilateral b)isosceles c) right angled d) none​

Answer 1

Answer:

isosceles triangle.

Step-by-step explanation:

Given, cos

2

A+cos

2

C=sin

2

B

Obviously it is not an equilateral triangle because A=B=C=60

∘

does not satisfy the given condition.

But B=90

∘

, then sin

2

B=1 and cos

2

A+cos

2

C=cos

2

A+cos

2

(

2

π

−A)=cos

2

A+sin

2

A=1

Hence, the satisfies the condition, so it is a right angled triangle but not necessarily isosceles triangle.

Answer 2

Answer:

its option b isosceles