Answer:
13) Rectangle
14) parallelogram
15) co ordinates areD (0,a) andE (c,b)
16) co ordinates are D(0,b) and E(a,0)
17)(-1,1) (4,1) (-1,4)
18)(0,0) (a,0) (a,a) (0,a)
Explanation:
13)
Rectangle
The opposite sides of a rectangle are parallel and equal
left height = right height
(by using distance formula)
(0,3),(2,-2) = (5,5),(7,0)
√(2-0)²+(-2-3)² = √(7-5)²+(0-5)²
√(2)²+(-5)² = √(2)²+(-5)²
√4+25 = √(2)²+(-5)²
√29 = √29 hence equal
14)
parallelogram
The opposite sides of a rectangle are not equal
left height = right height
(by using distance formula)
(0,0),(3,-4) = (3,4),(7,0)
√(3-0)²+(-4-0)² = √(7-3)²+(0-4)²
√(3)²+(-4)² = √(5)²+(-4)²
√9+16 = √(25)+(16)
√(25) ≠√41
5 ≠ √41
15)
co ordinates are D(0,a) and E(c,b)
16)
co ordinates are D(0,b) and E(a,0)
since rhombus have equal opposite sides
17)
(-1,1) (4,1) (-1,4)
18)
(0,0) (a,0) (a,a) (0,a)