PSLE math triangles Flashcards
(26 cards)
What is a triangle?
A polygon with three edges and three vertices.
True or False: A triangle can have more than one right angle.
False
What is the sum of the interior angles of a triangle?
180 degrees.
Name the three types of triangles based on side lengths.
Equilateral, Isosceles, and Scalene.
Fill in the blank: An equilateral triangle has _____ equal sides.
three
What type of triangle has one angle greater than 90 degrees?
Obtuse triangle.
How do you calculate the area of a triangle?
Area = 1/2 × base × height.
True or False: An isosceles triangle has at least two sides of equal length.
True
What is the formula for the perimeter of a triangle?
Perimeter = side1 + side2 + side3.
What do you call a triangle with all sides of different lengths?
Scalene triangle.
Fill in the blank: The longest side of a right triangle is called the _____.
hypotenuse
What is the Pythagorean theorem?
a² + b² = c², where c is the hypotenuse.
True or False: The angles in a right triangle always add up to 180 degrees.
True
What is an altitude in a triangle?
A perpendicular segment from a vertex to the line containing the opposite side.
What is a median in a triangle?
A line segment joining a vertex to the midpoint of the opposite side.
Fill in the blank: An acute triangle has all angles less than _____ degrees.
90
How many lines of symmetry does an equilateral triangle have?
Three.
What is the relationship between the sides and angles of a triangle?
In a triangle, the longest side is opposite the largest angle.
True or False: All triangles are similar if they have the same angles.
True
What is a right triangle?
A triangle that has one angle equal to 90 degrees.
What is the circumcircle of a triangle?
The circle that passes through all three vertices of the triangle.
Fill in the blank: The sum of the lengths of any two sides of a triangle must be _____ the length of the third side.
greater than
What is a triangle’s centroid?
The point where the three medians intersect.
How many degrees are in each angle of an equilateral triangle?
60 degrees.
