Section 04
Activities, Training & Learning Games
Four interactive drills built on the lesson rules. Everything is scored instantly so you can see where you slip.
Game 1 — Missing Angle Sprint
Two interior angles are shown. Type the third one before the clock runs out.
Score 0/0 · 60s
Game 2 — Triangle Builder
Drag the three side lengths. The triangle only appears when the inequality is satisfied.
Valid triangle ✔
4 + 5 = 9 > 6
The two shorter sides reach past the longest side, so the triangle closes.
Game 3 — Exterior Angle Challenge
Use the exterior angle rule to find the missing measure. Keep your streak alive.
Streak 0
Find the measure of the exterior angle ∠ABD.
Game 4 — Can It Be a Triangle?
Sort each set of lengths (in cm). Add the two shortest sides and compare with the longest.
0/0 correct
9 , 5 , 4 cm
7 , 6 , 5 cm
10 , 5 , 2 cm
10 , 6 , 5 cm
8 , 4 , 4 cm
12 , 3 , 6 cm
3 , 4 , 5 cm
11 , 4 , 6 cm