Construct an equilateral triangle if its altitude is $3.2\text{cm.}$

Construct a right triangle with perimeter $11\text{cm}$ and one base angle as $30°.$

[Hint: The other base angle is $(180°-(90°+30°)=60°).$] 

Construct an isosceles right triangle with perimeter $12\text{cm.}$ 

Hint: The angles of right isosceles triangle are $45°,45°,90°.$