Unit 5 · Geometry
Acute Angle Turns — Minimum to Reach 360°?
Lesson 6 of 6
About this lesson
Maxine turns a dial through an acute angle each time. She needs at least one full revolution (360°). What is the fewest turns? The trap is option C (4): four times 90° = 360°, but 90° is a right angle, NOT acute. So 4 turns can never quite make 360°. Five turns of 72° each reaches exactly 360° — and 72° is acute.
Chapters
Question
Maxine turns a dial on a machine.
She follows this instruction repeatedly:
- Turn the dial clockwise through an acute angle.
After a while, she has turned the dial by at least one complete revolution.
What is the smallest number of times she could have followed the instruction?
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