Question

Nikki drew a rectangle with a perimeter of 18 units on a coordinate grid. Two of the vertices were (4, –3) and (–1, –3). What could be the coordinates of the other two vertices of the rectangle?

Answer 1

Answer:

There are two possible solutions for the other two vertices of the rectangle:

(i) (4, 1), (-1, 1), (ii) (4, -7), (-1, -7)

Step-by-step explanation:

Geometrically speaking, the perimeter of a rectangle ($p$) is:

$p = 2\cdot b + 2\cdot h$ (1)

Where:

$b$ - Base of the rectangle.

$h$ - Height of the rectangle.

Let suppose that the base of the rectangle is the line segment between (4, -3) and (-1, -3). The length of the base is calculated by Pythagorean Theorem:

$b = \sqrt{[(-1)-4]^{2}+[(-3)-(-3)]^{2}}$

$b = 5$

If we know that $p = 18$ and $b = 5$, then the height of the rectangle is:

$2\cdot h = p-2\cdot b$

$h = \frac{p-2\cdot b}{2}$

$h = \frac{p}{2}-b$

$h = 4$

There are two possible solutions for the other two vertices of the rectangle:

(i) (4, 1), (-1, 1), (ii) (4, -7), (-1, -7)