Construct a whose perimeter is 12 cm and whose base angles are 45° and 60°.

Step 1: Draw the line segment PQ = 12cm

Step 2: Construct the base angles at P and Q i.e. <XPQ=45° and <YQP=60°

Step 3: Bisect <XPQ and <YQP to meet at A

Step 4: Perpendicularly bisect AP and AQ to meet the bases at B and C respectively

Step 5: Join AB and AC to get the required triangle

So, ∆ABC is the required triangle

AB+BC+BC = 12cm

Base angles <ABC=45° and <ACB=60°