A triangle has two corners with angles of pi / 4 π4 and pi / 4 π4. If one side of the triangle has a length of 16 16, what is the largest possible area of the triangle?

1 Answer
Mar 26, 2017

128

Explanation:

The angles of a triangle have to sum up to piπ and since two of the angles are both pi/4π4, the remaining angle must be pi/2π2. Knowing special triangles, this is a right triangle where the two legs are the same length and the hypotenuse is sqrt22 times the legs.

One of the sides of the triangle has a length of 1616. We can set that to be either the leg length or the hypotenuse length. Intuitively setting it as the leg length will give a larger triangle because the sides will be longer: 16, 16, and 16sqrt2~~22.616,16,and16222.6 instead of 16/sqrt2~~11.3, 16/sqrt2~~11.3, and 1616211.3,16211.3,and16.

Since our largest triangle has the largest area, we know that the first set is what we're looking for.

Since this is a right triangle with legs 16 and 16, the area is 16^2/2=1281622=128