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Exactly Reaching

Part of the Triangles section of Coddy's Geometry journey. Lesson 2 of 60.

Sticks of 5 and 5 met above the 8, with room to spare. Now try sticks of 3 and 5. Together they are exactly 8 long. Can they make a triangle?

$A stick 8 long lying down, with sticks of 3 and 5 hanging from its ends$

Challenge

AB is 8 long. Drag C until AC = 3 and BC = 5 at the same time. Where does C end up? Then press Check.

Try it yourself

$Drag the figure and watch$

Drag the figure and watch

All lessons in Triangles

1The Triangle Inequality

Can Three Sticks Meet?Exactly ReachingThe Range of the Third Side Recap: The Third Side

4Area of a Triangle

Half the Rectangle Height Is Not a Side Right Triangle Area Finding the Height Any Side Can Be the Base Recap: Area

7Is It Right?

The Converse Testing a Triangle Acute or Obtuse?Sorting by the Test Recap: Right or Not

10Scale in the World

Shadows Across the River Nested Triangles A Side with an Expression Recap: Scale in the World

2Sides and Names

Sorting by Sides The Longest Side Ticks into Equations Recap: Sorting Triangles

5The Pythagorean Theorem

Squares on the Sides Finding the Hypotenuse Pythagorean Triples When It Is Not Whole Recap: The Hypotenuse

8Special Right Triangles

The 45-45-90 Triangle Legs from the Hypotenuse The 30-60-90 Triangle All Three Sides Which Triangle Is It?Recap: Special Triangles

11Two Tools at Once

Height of an Isosceles Area from the Height The Equilateral Triangle Right Triangle Perimeter Recap: Two Tools