Star Camp Telescope Turns: Counting One-Degree Angles

Every click turns the telescope 1°. Count the clicks to find the angle.

Answer Key

One click, one degree

At star camp, the telescope turns one click at a time. Each click turns it through a one-degree angle, which measures 1°.

Rosa turns the telescope 40 clicks to point it at the Moon. What is the measure of the angle it turns through?

The angle measures 40 degrees.

Dev turns the telescope through an angle that measures 75°. How many one-degree clicks did he make?

Dev made 75 one-degree clicks.

Match each turn of the telescope to the kind of turn it makes.

90 one-degree anglesD
180 one-degree anglesA
360 one-degree anglesB
45 one-degree anglesC

A. a half turn
B. a full turn
C. half of a right angle
D. a right angle (a quarter turn)

Two telescopes sit side by side. The big telescope is 6 feet long. The small telescope is 2 feet long. Each one turns 30 clicks. Which sentence is true?

A. The big telescope turns through a larger angle.
B. Both telescopes turn through an angle of 30°.
C. The small telescope turns through a larger angle.
D. The big telescope turns through 180° because 6 × 30 = 180.

Read the protractor

The telescope starts at the 0 mark. The numbers count one-degree angles from 0, and each short mark is halfway between two numbers.

Wes turns the telescope from the 0 mark to the ray shown.

The telescope turns through 135 one-degree angles.
So the angle measures 135 degrees.

Priya turns the telescope from the 0 mark to the ray shown. What is the measure of the angle?

A. 60°
B. 115°
C. 65°
D. 70°

Hana wants the telescope to point straight up, at the 90 mark. Right now it points along the ray shown.

Right now the telescope points at the 35 mark.
It needs 55 more one-degree clicks to reach the 90 mark.

The telescope turned from the 0 mark to the ray shown. Which sentences are true? Choose all that are true.

A. The angle is made of 120 one-degree angles.
B. The angle is made of 125 one-degree angles.
C. The angle measures 55°.
D. The angle measures 125°.

Star camp challenges

Each click is still a one-degree turn. All the turns go in the same direction.

To follow a star across the sky, the telescope turns 2 clicks every minute. How many degrees does it turn in 25 minutes?

The telescope turns 50 degrees in 25 minutes.

10.

Ava turns the telescope 25 clicks, then 40 clicks, then 15 clicks. What is the measure of her whole turn?

Ava's whole turn measures 80 degrees.

11.

Sort each telescope turn. Is it less than or more than a right angle (90°)?

89 one-degree angles120 one-degree angles45 clicks, then 50 more clicks60 clicks, then 25 more clicks91 one-degree angles

Less than 90°	More than 90°
89 one-degree angles 60 clicks, then 25 more clicks	120 one-degree angles 45 clicks, then 50 more clicks 91 one-degree angles

12.

Explain how you know that a turn of 72 one-degree angles measures 72°.

Each one-degree angle measures 1°. The turn is made of 72 of them with no gaps or overlaps, so it measures 72 × 1° = 72°.