Determine if triangle is right or not

Question

Determine whether a triangle with sides of lengths 3, √21, and 7 units is a right triangle.

Answer 1

3² + (√21)² = 7²

If true then the triangle is right.

Answer 2

sides 3, sqr21 and 7

3^2 +(sqr21)^2 = 9 + 21 = 30

30 doesn't = 7^2=49

so it's Not a right triangle

Answer 3

To determine if a triangle is right, we need to use the Pythagoras theorem:

1. a² + b² = c²
2. ^{a = side 1}
3. ^{b = side 2}
4. ^{c = side 3}

^{Let a = 3}

^{Let b = sqrt(21)}

^{Let c = 7}

Therefore,

a² + b² =? c² =>

(3)² + (sqrt(21))² =? (7)² =>

9 + 21 =? 49 =>

30 != 49

Since 30 does not equal 49, we can conclude this is not a right triangle