<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/WebSite>
<https://www.wyzant.com/resources/answers/3321/abc_has_vertices_a_0_6_b_4_6_and_c_1_3_find_the_slope_then_the_orthocenter_of_abc_list_your_steps>