Classifying by Sides
A triangle with all angles < 90 degrees.
What is an acute triangle?
Sometimes, Always, Maybe:
An equilateral triangle is an isosceles triangle.
What is ALWAYS? (An equilateral triangle will always have at least 2 equal sides----because it already has 3 equal sides)
Which of the following can a scalene triangle be?
a) equilateral, b) right, c) obtused, d) acute, e) isoceles
What is b, c, d?
A triangle with at least 2 equal sides.
What is an isosceles triangle AND an equilateral triangle?
Sometimes, Always, Maybe:
An equilateral triangle is a right triangle.
What is NEVER? (An equilateral triangle must have all equal sides so therefore it can never have all 90 degree angles because all angles must add up to 180 degrees)
Which of the following can an equilateral triangle be?
a) scalene, b) right, c) obtuse, d) acute, e) isoceles
What is d and e?
A triangle with no equal sides.
What is a scalene triangle?
Draw an equilateral triangle, with lines of symmetry
What is "Show teacher triangle with all angles equal."
Sometimes, Always, Maybe:
A scalene triangle is an obtuse triangle.
What is SOMETIMES? (A scalene triangle can sometimes have an obtuse angle. It can also be acute as well as a right triangle; therefore it can only sometimes be obtuse)
Which of the following can an acute triangle be?
a) equilateral, b) right, c) obtuse, d) scalene, e) isoceles
What is a, d, and e?
What is an impossible combination of triangle classifications?
What is an equilateral obtuse triangle
Draw a right, scalene triangle, with lines of symmetry
Make sure you have a right angle and no sides are congruent.
A triangle with the following angle measurements: 97 degrees, 40 degrees, and 43 degrees.
What is an obtuse triangle?
Sometimes, Always, Maybe
An isosceles triangle is an equilateral triangle.
What is SOMETIMES?
(An isosceles triangle can only sometimes be equilateral. Sometimes isosceles only have two equal sides instead of all three.)
Which of the following can an isosceles triangle be?
a) equilateral, b) right, c) obtuse, d) acute, e) scalene
What is a, b, c, d?
The sides of an isosceles triangle could measure the following: A) 6", 7", 8" B) 9", 9", 9" C) 6", 9", 11" D) 6", 6.5", 7"
What is B, 9", 9", 9"?
Draw a triangle that is obtuse and scalene.
What is a triangle with an obtuse angle and no equal sides.
What classification (by angles) would an equilateral triangle be?
What is an acute triangle?
Sometimes, Always, Maybe:
An acute triangle is an equilateral triangle.
What is SOMETIMES?
(Sometimes an acute triangle can have all equal sides, but an acute triangle can also have just two equal sides as well as all sides of unequal lengths.)
Which of the following can a right triangle be?
a) equilateral, b) scalene, c) obtuse, d) acute, e) isoceles
What is b and e?