Quadrilateral abcd is inscribed in this circle. what is the measure of ∠a ? a quadrilateral inscribed in a circle. the vertices of the quadrilateral lie on the edge of the circle and are labeled a, b, c, d. the interior angle c is labeled as 74 degrees.

Angles A and C are supplementary when the quadrilateral is inscribed in a circle.
  ∠A = 180° - ∠C
  ∠A = 180° - 74° = 106°

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )