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Given triangle GFY with vertices at (-2,-3) (4,-1) and (1,8) respectively prove using BOTH methods (distance and slope) this is a right triangle. ​

User Reeses
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Triangle GFY is right angle triangle because it satisfies both methods (distance and slope) for right triangle.

How to prove that a triangle is a right angle triangle.

Method 1: Distance Criteria

Calculate Distances:

GF: √{(4 - (-2))² + ((-1) - (-3))³}

= √{6² + 2²} = {36 + 4}

= √40 = 2√10

GY : √{(1 - (-2))² + (8 - (-3))²}

= √{3² + 11²} = √{9 + 121} = √130

FY: √(1 - 4)² + (8 - (-1))²}

= √{(-3)² + 9²} = √{9 + 81}

= √90 = 3√10

Pythagorean Theorem:

GY² = FY² + GF²

(√130)² = (3√10)² + (2√10)²

130 = 90 + 40

130 = 130

Since the equation is satisfied triangle GFY is a right triangle based on the distance criteria.

Method 2: Slope Criteria

Calculate Slopes:

mGF = (-1 - (-3)/(4 - (-2))

= 2/6 = 1/3

mGY = (8 - (-3))/(1 - (-2))

= 11/3

mFY = (8 - (-1))/(1 - 4)

= 9/-3 = -3

Product of Slopes:

mGF * mGY = 1/3*11/3 = 11/9

mGY *mFY = 11/3*-3 = -11

mGF * mFY = 1/3 *-3 = -1

Since mGF *mFY = -1 triangle GFY satisfies the slope criteria, and it is a right triangle based on the slope criteria.

User Pcu
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