Construct an isosceles triangle whose base is 6 cm and whose vertical angle is 75 degree.

Steps of construction are as follows :

Step 1 : Draw AB = 6 cm

Step 2 : With A as centre draw rays AX such that ∠BAX = 75°

Step 3 : With B as centre draw Ray BY such that ∠ABY = 75° cutting AX at C

Now ABC is the required triangle with base AB and ∠CAB = ∠CBA = 75°