What is the（）of the turning circle in mavoeuvring?

If the ratio of the area of a sector to the area of the circle is 2：3. what is the ratio of the length of the arc in the sector to the circumference of the circle?

In the construction of a diesel engine, what is the purpose of end plates?（）

What is the purpose of the OSPF router ID in a OR/BOR election?（）

What is the purpose of sub cooling R-12 in the condenser?（）

Battens are fitted in cargo holds across the frames of the vessel from the turn of the bilge upward. The purpose of these cargo battens is（）.

Battens are fitted in cargo holds across the frames of the vessel from the turn of the bilge upward. The purpose of these cargo battens is（）.

Line segment AB is a diameter of circle O. If the coordinates of O are(2, -1)and the coordinates of point A are (-1, -2), what are the coordinates of point B?

Circles O and P intersect at exactly one point, as shown in the figure above. If the radius of circle O is 2 and the radius of circle P is 6, what is the circumference of any circle that has OP as a diameter?

Points X and Y are on a circle with center O, and point Z is on the longer arc of the circle between X and Y. If the measure of angle XOY is 135, the length of arc XZY is what fraction of the circumference of the circle?____

In the figure above, OACB is a square with area 4×2. If OA and OB are radii of a sector of a circle O, what is the perimeter, in terms of x, of the unbroken figure?

If the measures of the angles of a triangle are in the ratio of 3: 4: 5, what is the measure of the smallest angle of the triangle?