Question

Calculate the measure of arc AG if a=20 and b=10

Answer 1

90°

Explanation:

∆GFD is an isosceles right triangle, so angle FDG is 45°. Segment DF bisects angle EDG, so that angle is 90°.

Arc AG is the other half of the semicircle AGE that includes 90° arc GE.

So, arc AG is 90°.

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Comment on the problem

"a" and "b" are irrelevant to arc AG. They come into play for arc CE.