Question

Which is the measure of minor arc DE?

A. 60°
B. 70°
C. 80°
D. 90°

Answer 1

C. 80°

Explanation:

A circle adds to 360 degrees

AB +BC + CD +DE +EF + FA = 360

20 + 30+ 50+ DE +100 + 80 = 360

Combine like terms

280+DE = 360

Subtract 280 from each side

280-280+DE = 360-280

DE = 80

Answer 2

C

Explanation:

The total of the arc measures is 360

DE is the only one that hasn't got a marking. Add up all the rest

80 + 20 + 30 + 50 +DE + 100 = 360 Add the left side

280 + DE = 360 Subtract 280 from both sides

280 - 280 + DE = 360 - 280

DE = 80

The answer is C