Write T in the blank if the statement is true and F if it is false. _____ 1. If a building is a regular pentagon, the five outside walls as its sides are equal and five corners as its angles are equal in measure too. _____ 2. Irregular polygons cannot be pentagons, hexagons and nonagons. _____ 3. A triangle with three congruent sides is called an isosceles triangle. _____ 4. Square is an irregular polygon. _____ 5. Polygons with unequal sides and unequal angles are irregular polygons. ​.