Grade 12 · Math

Convert degrees to exact radians

Express common degree angle measurements as exact multiples of π radians.

6 authored questions + worked example

Worked example

Convert 30° to radians. Give an exact answer.

Answer & why

Answer: π/6 rad

A half turn is 180° or π radians. Multiply 30 by π/180 to get π/6 rad.

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All questions

All 6 authored questions for this skill.

Question 1

Convert 60° to radians. Give an exact answer.

  1. π/6 rad
  2. 2π/3 rad
  3. 7π/3 rad
  4. π/3 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: π/3 rad

A half turn is 180° or π radians. Multiply 60 by π/180 to get π/3 rad.

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Question 2

Convert 90° to radians. Give an exact answer.

  1. π rad
  2. π/4 rad
  3. 5π/2 rad
  4. π/2 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: π/2 rad

A half turn is 180° or π radians. Multiply 90 by π/180 to get π/2 rad.

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Question 3

Convert 120° to radians. Give an exact answer.

  1. 2π/3 rad
  2. 4π/3 rad
  3. 8π/3 rad
  4. π/3 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: 2π/3 rad

A half turn is 180° or π radians. Multiply 120 by π/180 to get 2π/3 rad.

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Question 4

Convert 180° to radians. Give an exact answer.

  1. 2π rad
  2. 3π rad
  3. π rad
  4. π/2 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: π rad

A half turn is 180° or π radians. Multiply 180 by π/180 to get π rad.

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Question 5

Convert 30° to radians. Give an exact answer.

  1. π/6 rad
  2. 13π/6 rad
  3. π/12 rad
  4. π/3 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: π/6 rad

A half turn is 180° or π radians. Multiply 30 by π/180 to get π/6 rad.

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Question 6

Convert 45° to radians. Give an exact answer.

  1. 9π/4 rad
  2. π/8 rad
  3. π/2 rad
  4. π/4 rad
A hint

Multiply a degree measurement by π/180; simplify the numeric fraction.

Answer & why

Answer: π/4 rad

A half turn is 180° or π radians. Multiply 45 by π/180 to get π/4 rad.

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