Which figure has rotational symmetry?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

You are designing a rectangular pet pen for your new baby puppy. you have 30 feet of fencing you would like the fencing to be 6 1/3 feet longer than the width

On #16 : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.