Question

Using Slopes of Parallel Lines Quick Check

Answer 1

Answer:

The answer is (B) ⇒ Yes. AB is parallel to CD and AD is parallel to BC

Step-by-step explanation:

There is an important fact about the parallel lines:

• Parallel lines have equal slopes

The rule of the slope of a line is:

• $m=\frac{y_{2}-y_{1} }{x_{2}-x_{1}}$, where $(x_{1},y_{1})$ and $(x_{2},y_{2})$ are two points on the line

Let us use the fact and the rule to solve the question

∵ ABCD is a quadrilateral

∵ A = (0, 2) , B = (2, 6), C = (9, 6), D = (7, 2)

∵ The opposite sides are AB, CD and AD, BC

Find the slopes of the four sides to check the parallel sides

∵ $m_{AB}=\frac{6-2}{2-0}=\frac{4}{2}=2$

∵ $m_{CD}=\frac{2-6}{7-9}=\frac{-4}{-2}=2$

∵ The slope of AB = The slope of CD

∴ AB // CD

∵ $m_{AD}=\frac{2-2}{7-0}=\frac{0}{7}=0$

∵ $m_{BC}=\frac{6-6}{9-2}=\frac{0}{7}=0$

∵ The slope of AB = The slope of CD

∴ AD // BC

The correct answer is:

Yes. AB is parallel to CD and AD is parallel to BC ⇒ (B)