Question

What is the value of b? 75 100 90 80

Answer 1

Hello from MrBillDoesMath!

Answer:

80

Discussion:

Per the attachment,  arc AB spans 110 degrees and arc BC spans 90 degrees (as that is the measure of the central angle subtending it). Hence arc ABC spans 110 + 90 = 200 degrees. As a circle has 360 degrees the smaller arc CA spans  360 - 200  = 160 degrees.  But angle"b" is a tangent chord angle so its measure equals 1/2 the arc spanned, that is 1/2 ( 160 ) = 80 degrees

Thank you,

MrB