prove converse pythogorus therom
Answers
Answer:
The converse of the Pythagorean Theorem is: If the square of the length of the longest side of a triangle is equal to the sum of the squares of the other two sides, then the triangle is a right triangle.
Step-by-step explanation:
Statement:
In a Triangle the square of longer side is equal to the sum of squares of the other two sides, then the triangle is a right angled triangle.
Given -
A Triangle ABC such that
BC² = AB² + AC²
To Prove -
Angle A = 90°
Construction -
Draw a ∆DEF such that AB = DE and AC = DF and Angle D = 90°
Proof -
In ∆ABC,
BC² = AB² + AC² - Given
In ∆ DEF
EF² = DE² + DF²
Therefore,
EF² = AB² + AC²
(Since AB = DE, AC = DF)
Therefore,
BC² = EF² ie - BC = EF
Now, In ∆ABC and ∆DEF
AB = DE - By Construction
AC = DF - By Construction
BC = EF
Therefore
∆ABC ≅ ∆DEF by SSS test.
Thus,
Angle A = Angle D - CPCT
But, Angle D = 90° ( As per construction)
Therefore
Angle A = 90°
Hence Proved!