The coordinates of quadrilateral ABCD are A(-1, -5), B(8,2), C(11,13) and D(2,6). 1- prove ABCD is a parallelogram
2- prove ABCD is a rhombus

How do you determine whether a relationship represented as as graph is linear or nonlinear

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

Aschool had an election where the candidates received votes in the ratio 1: 2: 3. if the winning candidate received 210 votes, how many total people voted in the election?