Home>Article>Backend Development> PHP algorithm exercise 8: Determine whether the given three numbers can form a right triangle
In this article "PHP Algorithm Exercise 7: Judgment Method for Implementing Geometric Sequences", I will introduce to you how to use PHP to judge geometric sequence. Interested friends can learn about it~
This article will continue to introduce you to the PHP algorithm series knowledge. As the title states, this time it will teach you how to judge whether a right triangle can be formed by given three numbers. I can be sure that it is at least 99% My friends all did this kind of math problems when they were students! ! !
So first of all, I want to introduce to you the methods of determining right triangles:
1: A triangle with an angle of 90° is a right triangle.
#2: If a² b²=c² is satisfied, then it is a right triangle with c as the hypotenuse and ab as the right side (according to the converse theorem of the Pythagorean theorem).
3: If the side opposite to a 30° internal angle of a triangle is half of a certain side, then the triangle is a right triangle with this long side as the hypotenuse.
#4: A triangle with two mutually complementary acute angles is a right triangle.
5: If you want to prove that right triangles are congruent, you can use HL. The lengths of the hypotenuses of two triangles are equal, and the lengths of one right-angled side are equal, then the two right triangles are congruent. [Theorem: Two right triangles are congruent if the hypotenuse and a right angle are equal. Abbreviated as HL]
#6: If two straight lines intersect and the products of their slopes are negative reciprocals of each other, then the two straight lines are perpendicular.
#7: In a triangle, if the midline on one side is equal to half of the side where the midline is located, then the triangle is a right triangle.
Okay, I have introduced you to so many methods of determining right triangles. I think everyone has a clue about how to use PHP to determine them.
I will go directly to the code below:
The PHP code is as follows:
The judgment result is:
是Here In this code, we have given three numbers: 5, 3, and 4;
Then we can calculate according to the Pythagorean Theorem to see whether these three numbers meet the requirements. It is obvious: 3 squared 4 The square of is equal to the square of 5.
That is to say, the three numbers we gave can form a right triangle.
Here is a brief introduction to the PHP assignment operator
*=
For example: x *= y, it means x = x * y; then $a in the above code *= $a; can represent the square of $a~
Finally, I would like to recommend the latest and most comprehensive "PHP Video Tutorial"~ Come and learn!
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