The Distance Formula & Pythagorean Theorem

Day 90Learning Target:Students can find the distance between 2 points using the distance formula.

Review the HWReview the HW

11, yx 22 , yx

2 22 1 2 1( ) ( )D x x y y

The Distance The Distance FormulaFormula

Example Find the distance between (1, 4) and (-2, 3). Round to the nearest hundredths.

D = 3.16

2122

12 )()(D yyxx

22 )43()12(D

22 )1()3(D

19D

10D

Example

Find the distance between the points, (10, 5) and (40, 45). Round to the nearest hundredths.

2122

12 )()(D yyxx

22 )545()1040(D

22 )40()30(D

1600900D

2500D

D = 50

3. Find the distance between the points. Round to the nearest tenths.

( ) ( )4 1 2 02 2

9 413

2122

12 yyxx

4. Find the distance between the points. Round to the nearest tenths.

2122

12 yyxx

Pythagorean Pythagorean TheoremTheorem2 2 2leg leg hyp

Pythagorean Theorem Word Pythagorean Theorem Word ProblemsProblems

• A square has a diagonal with length of 20 cm. What is the measure of each side? Round to the nearest tenths.

Pythagorean Theorem Word Pythagorean Theorem Word ProblemsProblems

• A 25 foot ladder is leaning against a building. The foot of the ladder is 15 feet from the base of the building. How high is the top of the ladder along the building? Round to the nearest tenths.

Pythagorean Theorem Word Pythagorean Theorem Word ProblemsProblems

• Ashley travels 42 miles east, then 19 miles south. How far is Ashley from the starting point? Round to the nearest tenths.

Pythagorean Theorem Word Pythagorean Theorem Word ProblemsProblems

• What is the length of the altitude of an equilateral triangle if a side is 12 cm? Round to the nearest tenths.

ClassworkClasswork Round to the nearest tenths.

Worksheet

Classwork / Classwork / HomeworkHomework

Quadrilaterals Task