1-c 2-b 3-a 5-b 6-c 7-b 8-b 9-a 10-a 11b 12-a 13-b 14-b 15c
<span>1) Perpendicular means at right angle to another line or plane
2) Triangles have three sides.
3) Squares have four sides and their sides are equal.
4) Tranles, squares and rectangles have four sides</span>
Я считаю, что должен быть такой порядок DBAEC