Question

AB is a diameter. 48° B A What is the measure of BC? 180° 84 42° 96°​

Answer 1

Answer:

84°

Step-by-step explanation:

The central angle of a circle is twice any inscribed angle subtended by the same arc.

because AB is a diameter, we also know that the triangle angle at C is 90° (all the inscribed triangles with their baseline being a diameter are right-angled).

as always, the sum of all angles in a triangle is 180°.

so, we know the triangle angle at A is

180 - 90 - 48 = 42°.

this is also the inscribed angle of the arc BC.

the central angle for arc BC (that is what is requested here) is then twice that angle : 2×42 = 84°