Question

if triangle rst is an acute triangle, then m∠s must be
○ less than 90°.
○ equal to 90°.
○ equal to 100°.
○ greater than 90° and less than 180°.

Explanation:

An acute triangle has all angles less than 90°. So each angle, including ∠S, must be less than 90°.

Answer:

less than 90°