Angles around a point

Difficulty Starter · Set s3ojbh

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1
3 angles meet at a point. 2 of them are 60°, 30°. What is the last one, in degrees?
2
3 angles meet at a point. 2 of them are 40°, 60°. What is the last one, in degrees?
3
3 angles meet at a point. 2 of them are 80°, 60°. What is the last one, in degrees?
4
3 angles meet at a point. 2 of them are 80°, 20°. What is the last one, in degrees?
5
3 angles meet at a point. 2 of them are 80°, 110°. What is the last one, in degrees?
6
3 angles meet at a point. 2 of them are 40°, 40°. What is the last one, in degrees?
7
3 angles meet at a point. 2 of them are 50°, 110°. What is the last one, in degrees?
8
3 angles meet at a point. 2 of them are 30°, 60°. What is the last one, in degrees?
9
3 angles meet at a point. 2 of them are 40°, 130°. What is the last one, in degrees?
10
3 angles meet at a point. 2 of them are 20°, 20°. What is the last one, in degrees?
11
3 angles meet at a point. 2 of them are 80°, 30°. What is the last one, in degrees?
12
3 angles meet at a point. 2 of them are 50°, 70°. What is the last one, in degrees?
13
3 angles meet at a point. 2 of them are 60°, 60°. What is the last one, in degrees?
14
3 angles meet at a point. 2 of them are 50°, 60°. What is the last one, in degrees?
15
3 angles meet at a point. 2 of them are 90°, 80°. What is the last one, in degrees?
16
3 angles meet at a point. 2 of them are 70°, 60°. What is the last one, in degrees?
17
3 angles meet at a point. 2 of them are 80°, 30°. What is the last one, in degrees?
18
3 angles meet at a point. 2 of them are 20°, 150°. What is the last one, in degrees?
19
3 angles meet at a point. 2 of them are 90°, 30°. What is the last one, in degrees?
20
3 angles meet at a point. 2 of them are 110°, 50°. What is the last one, in degrees?

What is in this set

The numbers in this set run from 2 to 150.
Every problem in it will meet at a point, so they add to 360°.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 70% of the problems: angles round a whole point add to 360°, not 180° — 180° is a straight line.
Answers are a whole number.

Drawing 240 problems from this page produced 94 different ones, 39% — so a sheet of 20 will come back to a problem you have seen — there are only so many sensible ones of this kind.

The same skill, harder or easier

We would put this in front of a grade 6 class. That is our judgement, not a standard, and it is printed here so you can disagree with it. Everything else we put in that year.