Curriculum · Geometry · Triangles
The Triangle Toolkit
Congruence, the triangle inequality, medians, altitudes, and area formulas.
Objectives
- Prove triangles congruent
- Apply the triangle inequality
- Compute area five ways
The full interactive edition of this lesson ships in v1.5. The topic is live everywhere else — the problems below feed your Triangles mastery now.
Train the topic
●●○○○A right triangle has legs and . What is the length of the hypotenuse?AMC 8 style●●○○○The sides of a triangle are and . How many integer values can the third side take?AMC 8 style●●●○○What is the area of a triangle with sides , , ?AMC 10 style●●●○○An equilateral triangle has side length . Its area is with squarefree. What is ?AIME style