converse to the pythagorean theorem ch 7.2 converse to the pythagorean theorem if the square of the...

Converse to the Pythagorean Theorem

Ch 7.2

Converse to the Pythagorean Theorem

• If the square of the length of the longest side of a triangle is equal to the sum of the squares of the lengths of the 2 other sides, then the triangle is a right triangle.

Verifying that something is or is not a right triangle.1. First we determine which side would be the hypotenuse.

2. Second we plug the values into the Pythagorean theorem.

222 201525 400225625

625625

222 bac

Is it a right triangle?

222 bac

222 162124

256441576

697576

Theorem 7.3

Theorem 7.4

Classify the triangle as right, obtuse or acute.

15, 20, 25

SO ACUTE

8, 9, 10

9, 10, 15

Graphing Triangles

1. When graphing triangles first plot the 3 points.

2. Decide on your method.1. Find the slope and determine whether there are

perpendicular lines. (Only works with right triangles)

2. Find the distance of each side of the triangle, then plug it back into the Pythagorean Theorem.

Graphing Triangles

A (1, 5), B(1, 1), C(6, 1)What kind of triangle is the graphed triangle?

Graphing Triangles

A (2, 4), B(4, 1), C(7, 1)What kind of triangle is the graphed triangle?

Graphing Triangles

A (3, -2), B(1, 0), C(7, 2)What kind of triangle is the graphed triangle?Find the distance of each side of the triangle

Graphing Triangles

A (3, -2), B(1, 0), C(7, 2)

22 )02()17(BClineofD

22 )20()31( ABlineofD

22 )22()37( AClineofD

212

212 )()( yyxxd

10240436)2()6( 22

22844)2()2( 22

24321616)4()4( 22 222 cba 222 )102()24()22(

40328

Graphing trianglesA (-3, 5), B(0,-2), C(4, 1)

525916)3()4()21()04( 2222 BClineofD

58499

)52()30( 22

ABlineofD

651649

)51()34( 22

AClineofD

222 cba

655825

65585222

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