What type of number is 0.27820.27820, point, 2782?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?