Parts of a Triangle: Identifying and defining elements

Can a triangle have two right angles?

The sum of angles in a triangle is 180 degrees. Since two angles of 90 degrees equal 180, a triangle can never have two right angles.

No

Look at the two triangles below. Is EC a side of one of the triangles?

Every triangle has 3 sides, let's go over the triangle on the left side:

Its sides are: AB, BC, CA

This means that in this triangle, side EC does not exist.

Let's go over the triangle on the right side:

Its sides are: ED, EF, FD

This means that in this triangle, side EC does not exist.

Therefore, EC is not a side in either of the triangles.

No.

Which of the following is the height in triangle ABC?

Let's remember the definition of height of a triangle:

A height is a straight line that descends from the vertex of a triangle and forms a 90-degree angle with the opposite side.

The sides that form a 90-degree angle are sides AB and BC. Therefore, the height is AB.

AB

Given the following triangle:

Write down the height of the triangle ABC.

An altitude in a triangle is the segment that connects the vertex and the opposite side, in such a way that the segment forms a 90-degree angle with the side.

If we look at the image it is clear that the above theorem is true for the line AE. AE not only connects the A vertex with the opposite side. It also crosses BC forming a 90-degree angle. Undoubtedly making AE the altitude.

AE

Is the straight line in the figure the height of the triangle?

Yes

Is the straight line in the figure the height of the triangle?

Yes

Can a triangle have a right angle?

Yes

Is the straight line in the figure the height of the triangle?

No

Is the straight line in the figure the height of the triangle?

No

Is the straight line in the figure the height of the triangle?

No

Is the straight line in the figure the height of the triangle?

No

Is the straight line in the figure the height of the triangle?

No

Can a plane angle be found in a triangle?

No

According to figure BC=CB?

True

Is DE a side in the triangle BDC?

Not true

DB is a side in triangle ABC

Not true

AB is a side in triangle ADB

True

Is DE side in one of the triangles?

Not true

True or false:

DE not a side in any of the triangles.

True

Is the straight line in the figure the height of the triangle?

No