Static Equilibrium & Elasticity

The large quadriceps muscle in the upper leg terminates at its lower end in a tendon attached to the upper end of the tibia. The forces on the lower leg when the leg is extended are modeled as in figure b, where $T$ is the force in the tendon, $F_{g,leg}$ is the gravitational force acting on the lower leg, and $F_{g,foot}$ is the gravitational force on the foot. Find $T$ when the tendon is at an angle of $\phi = 25^\circ$ with the tibia, assuming $F_{g,leg} = 30.0\,N$, $F_{g,foot} = 12.5\,N$, and the leg is extended at an angle $\theta = 40^\circ$ with respect to the vertical. Also assume the center of gravity of the tibia is at its geometric center and the tendon attaches to the lower leg at a position one-fifth of the way down the leg.