Question

if cos A =21/29 Find cos B if A+B =90°​

Answer 1

cos A = B/ H

Cos A = 21 / 29

apply triangle rule here i.e.

Base of triangle is 21 and hypotenuse is 29 . So by this we can find perpendicular of triangle by pythagoras theorem and it come out to be 20.

now we have to find cos B

at this time hypotenuse remains the same but perpendicular becomes base