Solution :
Tan 25° = C4/BC
=> 0.466 = CF/60
=> C4 = 27.96
A4² = AC² + C4²
AC² = 60² + 40² = 5200
CF² = 781.76
4F² = 5200 + 781.76
=> AF² =5981.76
=> A4 = 77.3
length A4 = 77.3 cm
