Answer:
1.26 m^2 / s.
Step-by-step explanation:
The area A of the triangle = 1/2*7*12 sin x = 42 sin x where x is the angle between the lines.
Relation between the rates is
dA/dt + dA/dx * dx/dt
We are given that dx /dt = 0.06 rad/s.
A = 42 sin x
dA/dx = 42 cos x
So dA/dt = 42 cos x * 0.06
When x = π/3 ( I am assuming that π 3 means π divided by 3 ):
dA/dt = 42 cos π/3 * 0.06
= 1.26 m^2/s.