Classify an angle of 35 Easy

The question

Question: find what kind of angle 35° is.

1 Compare with 90° and 180°

There are five kinds of angles.

Each name says how big the angle is, next to 90° and 180°.

35 is less than 90.

Careful!

Look at the size next to 90° and 180°.

2 Name it

So 35° is acute.

3 Check

Let's check with the picture.

The dashed line up makes a square corner: 90°.

The dashed line to the left makes a straight line: 180°.

Our angle is smaller than the square corner.

So it is acute.

Let's look back.

First: compare with 90° and 180°.

Then: name it.

Last: check.

▶ Watch it solved

Classify an angle of 95 Medium

The question

Question: find what kind of angle 95° is.

1 Compare with 90° and 180°

There are five kinds of angles.

Each name says how big the angle is, next to 90° and 180°.

95 is more than 90, but less than 180.

Careful!

Obtuse is bigger than a square corner, but smaller than a straight line.

2 Name it

So 95° is obtuse.

3 Check

Let's check with the picture.

The dashed line up makes a square corner: 90°.

The dashed line to the left makes a straight line: 180°.

Our angle opens wider than the square corner, but not as far as the straight line.

So it is obtuse.

Let's look back.

First: compare with 90° and 180°.

Then: name it.

Last: check.

▶ Watch it solved

Classify a triangle with sides 6, 7, 10 by its angles Harder

The question

Question: find what kind of triangle has sides 6, 7, 10, by its angles.

1 Find the longest side

The longest side is 10.

We call it c.

The biggest angle is across from it.

2 Compare the squares

Square the two short sides: 6² is 36, 7² is 49.

Together: 85.

Square the longest side: 10² is 100.

85 is less than 100: c is too long for a right angle.

The angle across from c is wider than 90°.

Only the biggest angle decides the name.

Careful!

The longest side is across from the biggest angle.

So c is always the longest side.

3 Name it

So the triangle is obtuse.

Let's look back.

First: find the longest side.

Then: compare the squares.

Last: name it.

▶ Watch it solved