Question

The hypotenuse of a right triangle is 37 units long. Find the other two sides if the perimeter of the triangle is 84 units. Separate the numbers by a comma.

Answer 1

Answer:

The lengths of the legs are 12 and 35 units

Step-by-step explanation:

Let c represent the hypotenuse and a and b represent the legs.  Then the Pythagorean Theorem requires that a^2 + b^2 = c^2 = 37^2 = Hypotenuse^2

Also:  a + b + c = Perimeter = 84 units.  

Since c = 37 units, a + b + 37 units = 84 units, or a + b = 47 units, or a = 47 - b.

Then a^2 + b^2 = 37^2 becomes (47 - b)^2 + b^2 = 37^2, or 1369.  Therefore:

2209 - 94b + b^2 + b^2 = 1369.

Simplifying by combining like terms, we get:  

840 - 94b + 2b^2 = 0, which is a quadratic equation in standard form.

Reducing all terms by division by 2, we get:

420 - 47b + b^2 = 0.  Here the coefficients are a = 1, b = -47 and c = 420.

The discriminant is therefore b^2 - 4ac, or 529, whose square root is ± 23.

Then the b values of this quadratic in b are

      47 ± 23

b = -------------- , so that b is either 35 or 12

             2

and then side a has length a = 47 - b = 12  or  35.

Thus, a = 12 and b = 35, and c is given:  37.

Check:  Is 12^2 + 35^2 = 37^2 true?  Is 144 + 1225 = 1369?  YES

The lengths of the legs are 12 and 35 units.