Each internal angle of regular polygon is two times its external angle. Then the number of sides of the polygon is: 

The difference between the interior and the exterior angles of a regular polygon is 150^o. Find the number of sides in the polygon.

ΔABC is an equilateral triangle in which D, E and F are the points on sides BC, AC and AB, respectively, such that AD ⊥ BC, BE ⊥ AC and CF ⊥ AB. Which of the following is true?

In triangle ABC, F is the centroid. If AB=11 cm, BC=14 cm and AC=7 cm, then what is the value (in cm) of EF?

In ∆ABC, AC = BC and ∠BAC = 40°. If BC is extended to D such that BC = CD, find out ∠ADC = ?

An arc of 30 ° in one circle is double an arc in a second circle, the radius of which is three times the radius of the first. Then the angles subtended by the arc of the second circle at its center is 

Two circles intersect at A and B, P is a point on produced BA. PT and PQ are tangents to the circles. The relation of PT and PQ is 

In the given figure, ∠QRU = 72°, ∠TRS = 15° and ∠PSR = 95°, then what is the value (in degrees) of ∠PQR ?