1) Draw a base of 12.5 cm.
2) Draw bisectors of the angles given.Here,you need to draw 105°/2 = 52.5° and 30°/2 =15° from the ends of the segment.
3) Elongate them till they meet at a point. Say, this point is R.
4) Draw perpendicular bisectors for both the sides.
5) Elongate both the perpendicular bisectors till they meet at the base. These are points P and Q.
6) Join P and Q to R.
7) ∆PQR is complete.
Yay! We completed the construction.Recheck it by measuring the angles and the perimeter.