Answer:
18. Scalene
19. Quadrilateral
20. option i)
Step-by-step explanation:
18. A triangle whose all the three sides are different is called a scalene Triangle . Where are whose two sides are equal is called an isosceles triangle and whose all the sides are equal is called an equilateral triangle. Here all the sides are of different measurement hence it is a scalene triangle.
19. A polygon containing
3 sides is a triangle
4 sides is Quadrilateral
5 Sides is a Pentagon
6 sides is a Hexagon
8 Sides is Octagon
Our polygon contains four sides, it is hence a quadrilateral
20.
Option i)
In two congruent figures , the corresponding sides and angles are equal.
corresponding side of s is side measuring 14 ft and that of t is the side measuring 12 ft
Hence s = 14 and t = 12
corresponding angles of u is angle measuring 90° and that of r is the angle measuring 90°
Hence ∠u = 90° and ∠r=90°