Which expression is equivalent to 1/3 - 1/9?

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

Match the following reasons with the statements given to create the proof. 1. do = ob, ao = oc sas 2. doc = aob given 3. triangle cod congruent to triangle aob vertical angles are equal. 4. 1 = 2, ab = dc if two sides = and ||, then a parallelogram. 5. ab||dc if alternate interior angles =, then lines parallel. 6. abcd is a parallelogram cpcte

Given that s is the centroid of triangle mno, find sq.