Skip to content
Your progress

Checking your sign-in…

Who's learning?

Each profile keeps its own read lessons, badges, streak, and practice scores on this device.

Lesson 12 of 15

Checkpoint: roads, altitudes and rays

Show on a big screen

5 min

Text size

Four questions on the last three ideas. Feedback comes right away. Retry whenever you want.

Sticks of 6 cm and 9 cm are given. Which third stick can close into a triangle?

What is true of an acute-angled triangle?

Two angles at the ends of a side are 61° and 47°. What is the third angle?

Two angles at the ends of a side are 95° and 85°. What happens?

0 of 4 answered

Finish the checkpoint to complete this lesson — you can always retry for a better score.