How do you do phythagras

The formula is H² = B² + P²

hypotenise² = base² + perpendicular²

According to pythagoras theorum, the square of hypotenuse is equal to the sum of squares of other two sides.

Let us consider a right angled triangle ABC ... with AC as hypotenuse.

Now, according to pythagoras theorum, AC squared = AB squared + BC squared.