## Blog

### The Quest for 700: Weekly GMAT Challenge (Answer)

Yesterday, Integrated Learning posted a 700 level GMAT question on our blog. Today, they have followed up with the answer:

Explanation:

The length of any arc is the same fraction of its circumference as the arc angle is of 360°. We are told that the circle in this question has a radius of 10, so it must have a circumference of 20?.  Arc ac has a length of 50?/3, which is 5/6 of 20?.

Thus, the arc is 5/6 of the circle, and has an arc angle of 300°.  That means the opposite angle, the one opposite line segment ac is 60° (see figure).

Additionally, the radius of the circle is 10, and so each of the sides of the triangle coming out of the center are 10.  This means that angle a and angle c must be equal, and since the angle in the center of the circle is 60°, they must also be 60°.  This means the whole triangle is equilateral, and the third side, line segment ac, is also length 10.

Integrated Learning provides professional, experienced GMAT tutors throughout the United States.

#### Upcoming Events

• NYU Stern (Round 3)
• MIT Sloan (Round 2)
• UNC Kenan-Flagler (Round 3)
• USC Marshall (Round 3)
• Carnegie Mellon Tepper (Round 3)
• London Business School (Round 3)
• Cambridge Judge (Round 4)
• NYU Stern (Round 4)