Classify a triangle with angles 30, 60, 90

Step by step

The question

Question: find what kind of triangle has angles 30°, 60°, 90°.

1 Find the biggest angle

The biggest angle is 90°.

Only the biggest angle decides the name.

It is exactly 90°: a right angle.

Careful!

Every triangle has at least two acute angles.

So they do not decide.

Only the biggest angle does.

2 Name it

So the triangle is right.

3 Check

Let's check: the angles must add up to 180°.

They do.

So it is a real triangle, and it is right.

Let's look back.

First: find the biggest angle.

Then: name it.

Last: check.