4. A bird left its post and

flew in a triangular path. It

flew 21 yards south, 72

yards east and 75 yards

diagonally to end back at

the post. Is it a right triangle?

It is a right triangle

Explanation:

We are given the directions in which a bird flew to make a triangle.

We are required to determine whether the triangle is right angle.

What is a right triangle?

It is a triangle that has a right angle between the shorter sides or legs The triangle also obeys the Pythagoras theorem, such that the square of the two legs is equal to the square of the hypotenuse. Such that if the two legs are, a and b while c is the hypotenuse.

Then, a² + b² = c²

In this case;

Taking the legs as a = 21 yards and b = 72 yards and the hypotenuse, c = 75 yards.

Then we can determine whether it is a right triangle;

a² = 21² = 441

b² = 72² = 5184

c² = 75² = 5625

a² + b² = 5625

Therefore; a² + b² = c²

Hence, the triangle is right triangle.