Where a triangle comes from
What three lines leave behind
Take three straight lines and let each pair cross. If the three crossings are three different points, the lines enclose a triangle.
📚 Chapter Learning Kit
A Tale of Three Intersecting Lines · Class 7 Mathematics · Ganita Prakash
English 3 topics 105 leveled MCQs 51 flashcards 5 games Free
Shared by a Veda teacher · Generated with Veda AI · Oct 2026
⚡ Veda Bites
💡 Key Idea
💡 Key Idea
💡 Key Idea
💡 Key Idea
✏️ Example
💡 Key Idea
The whole idea, one bite at a time
Veda Bites are swipeable micro-lessons — each one teaches exactly one idea. Here's a taste from this kit; the app has the full deck.
What equilateral means
The most even triangle
A triangle with all three sides the same length is equilateral.
Nothing tells the corners apart
Why its angles must match
Turn an equilateral triangle, or flip it, and it looks exactly the same.
The most useful fact about triangles
Always one hundred and eighty
Draw any triangle at all and measure its three angles. They add to 180 degrees.
Tearing off the corners
Seeing why with scissors
Draw a triangle, tear off its three corners and lay them side by side with their points touching.
The same argument without tearing
Seeing why with a parallel line
Draw a line through one corner, parallel to the opposite side.
📖 Smart notes
What you'll study, topic by topic
1
Equilateral triangles, and when three lengths work
A triangle is what three intersecting lines enclose. An equilateral triangle has three 60 degree angles at every size. Three lengths make a triangle exactly when the two shortest together exceed the longest, and equality…
- Three lines enclose a triangle when their crossings are three different points.
- An equilateral triangle has all three sides the same length.
- Its angles must be equal, because nothing distinguishes its corners.
~35 min · full explanation, examples & memory tricks in the app
2
The angle sum, and what data fixes a triangle
The three angles of any triangle add to 180 degrees, which gives the third from two and checks any measurement. Two sides with the angle between them, or two angles with the side between them, fix exactly one triangle. T…
- The three angles of any triangle add to 180 degrees.
- Three torn corners laid together fit exactly along a straight line.
- A parallel line through a corner transfers two angles by alternate angles.
~40 min · full explanation, examples & memory tricks in the app
3
Naming triangles, and the lines inside them
A triangle is named twice over. By sides it is equilateral, isosceles or scalene. By angles it is acute, right-angled or obtuse. Only one angle can reach 90, so an equilateral is always acute. A median goes to a midpoint…
- Sides and angles are separate questions, so a triangle gets two labels.
- All sides equal is equilateral, exactly two equal is isosceles, all different is scalene.
- All angles under 90 is acute, one at 90 is right-angled, one over 90 is obtuse.
~40 min · full explanation, examples & memory tricks in the app
❓ Leveled MCQ practice
Try the smart MCQs from this kit
105 questions laddered from warm-up to topper-level, each with an explanation. A taste:
Three lines are drawn across a page and the places where they cross each other decide whether anything is enclosed. They enclose a triangle when their crossings are
Beginner
A two different points
B a single point
C three different points
D four different points
Show answer & explanation
three different points
Three separate corners are needed.
A triangle is built from three given lengths that all turn out to be the same as each other. Built that way, the triangle is
Beginner
A isosceles
B equilateral
C scalene
D right-angled
Show answer & explanation
equilateral
Equal sides all round.
Whatever shape a triangle takes, its angle total is
Beginner
A 180 degrees
B 360 degrees
C 90 degrees
D 270 degrees
Show answer & explanation
180 degrees
This is the fact the rest rests on.
An equilateral triangle has three equal angles and those angles together have to fill 180 degrees. Each of its angles measures
Beginner
A 45 degrees
B 60 degrees
C 90 degrees
D 30 degrees
Show answer & explanation
60 degrees
Three equal angles adding to 180.
🃏 Flashcards
Tap a card to flip it
51 flashcards in this kit — the app reviews them with spaced repetition so the right card returns on the right day.
🎮 Learning games
Play your way through this kit
Every game is built from this kit's own content — scores feed your mastery, so playing counts as studying.
Memory Match
Categorization
Fact Or Myth
Sequence Builder
Word Match
Playable in the app
Study it properly — free, in the app
The full Veda Bites deck, complete notes, spaced-repetition flashcards, leveled MCQs, tests and games for this kit — plus Daily Facts and the Arena, every day.