Please help me work through the below problem, thanks in advance!

The perimeter of a certain isosceles right triangle is 16+16√2. What is the hypotenuse of the triangle?

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- Dec 12th 2010, 08:40 AMmtylerroseDeriving hypotenuse from perimeter of a triangle
Please help me work through the below problem, thanks in advance!

The perimeter of a certain isosceles right triangle is 16+16√2. What is the hypotenuse of the triangle? - Dec 12th 2010, 08:48 AMsnowtea
Right triangle with side lengths a, b, c (where c is hypotnuse)

Isosceles means a=b

perimeter = a + b + c = a + a + c

Pythagorean theorem says: a^2 + b^2 = a^2 + a^2 = c^2

You have 2 equations and 2 unknowns. Solve for c. - Dec 12th 2010, 08:53 AMadkinsjr
first draw the triangle. If the hypotenuse is "b" and the 2 other equal sides are "a" then the perimeter is:

You know the angles of an isosceles right triangle, there are 2 45 degree angles and one angle

So the sine of pi over 4 is solve this for "a" and plug that into the original equation for the perimeter and use algebra to solve for "b". - Dec 12th 2010, 08:55 AMadkinsjr
Snowtea's solution is easier, I didn't catch that...

- Dec 12th 2010, 09:02 AMSoroban
Hello, mtylerrose!

Quote:

You should know that the sides of an isosceles right triangle are: .

The perimeter is: .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . .

Rationalize: .

. . . . . . . . .

The hypotenuse is: .

- Dec 12th 2010, 09:17 AMmtylerrose
Thanks everyone! I had no idea where to start, but now I am starting to understand.

Soroban,

How did you know to rationalize the way you did? - Dec 12th 2010, 11:46 AMadkinsjr