Postulates
It's Euclid's fourth postulate.
What is, 'That all right angles are equal to one another.'
It's Euclid's second common notion.
What is, 'If equals to be added to equals, the results are equal.'
They have two sides equal.
What is an isosceles triangle?
It's equilateral and right-angled.
What is a square?
It has both length and breadth.
What is a surface?
It's Euclid's third postulate.
What is, 'To describe a circle with any center and distance."
What is, 'Things which coincide with one another are equal to one another.'
It has an angle greater than a right angle.
What is an obtuse triangle?
It's right-angled but not equilateral.
What is an oblong?
A plane figure contained by one line such that all the straight lines falling upon it from one point among those lying within the figure are equal to one another
What is a circle?
It's Euclid's first postulate.
What is, 'To draw a straight line from any point to any point."
It's Euclid's fifth common notion.
What is, 'The whole is greater than the part.'
All its sides are equal.
What is an equilateral triangle?
It's equilateral but not right-angled.
What is a rhombus?
When a straight line set up upon a straight line makes the adjacent angles equal to one another, each of the equal angles is
What is a right angle?
It's Euclid's second postulate.
What is, 'To produce a straight line continuously in a straight line."
It's Euclid's first common notion.
What is, 'Things which are equal to the same thing are equal to one another.'
All its angles are less than a right angle.
What is an acute triangle?
It's neither equilateral nor right-angled, but its opposite sides and angles are equal.
What is a rhomboid?
Straight lines that don't meet, even when extended indefinitely.
What are parallel lines?
It's Euclid's fifth postulate.
What is "if a straight line falling on two straight lines makes the interior angles on the same side less than two right angles (180 degrees), the two lines will meet on that side if extended indefinitely"
It's Euclid's third common notion.
What is, 'If equals be subtracted from equals, the remainders are equal.'
All its sides are unequal.
What is a scalene triangle?
It doesn't fit into any of the above categories.
What is a trapezium?
It has boundaries that are straight lines.
What is a rectilineal figure?