A triangle has two corners with angles of ( pi ) / 3 and ( pi )/ 6 . If one side of the triangle has a length of 12 , what is the largest possible area of the triangle?

1 Answer
Dec 7, 2017

72sqrt3square units

Explanation:

First, we know that the angels of a triangle has to add up to pi. Therefore, we know that the leftover angle is pi-(pi/3+pi/6)=pi/2 which is a right angle. Therefore, we know that the triangle is a right triangle. We also know that this is the special "30-60-90" triangle. Therefore, we can figure out the sides while assuming 12 being one of each: the shortest, the middle, the longest.

Remember that in a "30-60-90" triangle, the shortest side is a, the second longest (middle) side is asqrt3 and the longest side is 2a.
Also, you multiply the two legs and then divide it by two to find the area of a right triangle.

When 12 is the hypotenuse, we know that the shortest side is 6 and the middle side is 6sqrt3 with the area of 18sqrt3

When 12 is the shortest side, we don't really care about the hypotenuse. The middle side is 12sqrt3 with the area of 72sqrt3.

When 12 is the middle side, we again don't care about the hypotenuse. The shortest side would be 12/sqrt3 which really is 4sqrt3 with the area of 24sqrt3. Out of these three, we see that 72sqrt3 is the largest possible area.