Standardized Test Practice - 1. Tools of Geometry - McGraw Hill Glencoe Geometry, 2012

To determine the distance between two points, we use the Distance Formula. The coordinates of the given points are

R (- 4, 5)

and

S (3, - 2) .

R S = (x_{2} - x_{1})^{2} + (y_{2} - y_{1})^{2}

Substitute $(- 4, 5)$ & $(3, - 2)$

R S = (3 - (- 4))^{2} + (- 2 - 5)^{2}

$a - (- b) = a + b$

R S = (3 + 4)^{2} + (- 2 - 5)^{2}

Add and subtract terms

R S = 7^{2} + (- 7)^{2}

$(- a)^{2} = a^{2}$

R S = 7^{2} + 7^{2}

Calculate power

R S = 49 + 49

$a + a = 2 a$

R S = 2 \cdot 49

$a \cdot b = a \cdot b$

R S = 2 \cdot 49

Calculate root

R S = 2 \cdot 7

R S = 72

Use a calculator

R S = 9.899494 \dots

Round to $1$ decimal place(s)

R S \approx 9.9

The distance between

R

and

S

is approximately

9.9 .

Exercise 8 Page 87