Question

no 34 is doubt please answer this question immediately its urgent

Answer 1

Here
Phi+theta+90°=180°
Phi+theta=90°
Phi=90°-theta
Cos(phi)=cos(90°-theta)
Cos(phi)=sin(theta)
From the figure,
Sin(theta) =4/5
Therefore, cos(phi) =4/5
The correct option is (d)

Answer 2

90+theta+phi=180 implies
theta +phi=90
phi =90-theta
cos(phi)=cos(90-theta)
implies cos(phi)=sin(theta)
we know that sin(theta)=4/5
(from figure)
therefore
cos(phi)=4/5

thank you.