Q. Find the measure of a negative angle coterminal with 90∘.____∘
Subtract 360° from 90°: To find a negative angle coterminal with 90°, subtract 360° from 90° because coterminal angles are separated by full rotations, which are 360°.Calculation: 90°−360°=−270°.
Verify −270° is coterminal: Check if −270° is indeed negative and coterminal with 90°. Coterminal angles have the same initial and terminal sides when drawn in standard position. Since 90° is a quarter turn from the positive x-axis, and −270° is three quarter turns in the negative direction, they end up in the same position.
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