1. greater than (3) and less than (13) (the sum of two sides is greater than the third side, and the difference between the two sides is less than the third side).

2. Let the minimum angle be an obtuse triangle of x+2x+6x =180x = 202x = 406x =120.

3. The long drawing part of a rectangle is a rectangle.

S=5*2π3=30π

4. s = base * height = 4.2/2.1= 2 decimeters.

5.S= (upper sole+lower sole) * Height /2 is wrong.

6. Perimeter =2*(4.28+2)= 12.56dm Square Side Length = 12.56/4=3. 14dm Area =3. 14 square.

Diameter of circle = perimeter /π=4 Area =4π

7. 12 side length =48/ 12=4cm S=6* side length * side length =96 volume = side length * side length * side length =64.