The side length ratio of a 30-degree right triangle is 1: √ 3: 2. A right triangle is a geometric figure with a right angle. There are two kinds of right-angled triangles: ordinary right-angled triangles and isosceles right-angled triangles. It conforms to Pythagorean theorem and has some special properties and judgment methods.

A formula is a formula that uses mathematical symbols to express a certain relationship (such as a law or theorem) between various quantities. It is universal and applicable to all similar problems. In mathematical logic, a formula is a formal grammatical object to express a proposition, but the proposition may depend on the free variable value of the formula.

Right triangle judgment method:

Judgment 1: A triangle with an angle of 90 is a right triangle.

Decision 2: If A? +b？ +c？ A triangle with sides a, b and c is a right triangle with hypotenuse c (the inverse theorem of Pythagorean theorem).

Decision 3: If the opposite side of the 30 internal angle of a triangle is half of a certain side, the triangle is a right triangle with this long side as the hypotenuse.

Decision 4: A triangle whose two acute angles are complementary angles (the sum of the two angles is equal to 90) is a right triangle.

Decision 5: If two straight lines intersect and the product of their slopes is negative reciprocal, then the two straight lines are perpendicular to each other. Then this triangle is a right triangle.

Decision 6: If the median line of one side of a triangle is equal to half of its side, then the triangle is a right triangle. Refer to the right triangle hypotenuse midline theorem.

Decision 7: A triangle with an angle of 30 is a right triangle if its opposite side is equal to half of its adjacent side.