Can a triangle be regular?
The definition of a regular shape is that all the sides are equal and all the inside angles are equal. An irregular shape doesn’t have equal sides or equal angles. For example, an equilateral triangle is a regular shape because all the sides are equal AND all the angles are equal.
Is an equilateral triangle always sometimes or never an obtuse triangle?
1 Expert Answer The sum of the three angles of a triangle equal 180°. A triangle cannot have two 90° angles, there an obtuse triangle is NEVER a right triangle. In an equilateral triangle, the three angles are equal. Since the three angles total 180°, they are each 60°.
What is sometimes true about a triangle?
A triangle has three sides, three vertices, and three angles. The sum of the three interior angles of a triangle is always 180°. The sum of the length of two sides of a triangle is always greater than the length of the third side.
What is considered a triangle?
A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry.
Is a triangle a regular polygon?
A few examples of regular polygons are a triangle, quadrilateral, pentagon, hexagon, heptagon, and a decagon.
Is a triangle always an equilateral triangle?
An equilateral triangle is a triangle whose sides are all equal. Every equilateral triangle is also an isosceles triangle, so any two sides that are equal have equal opposite angles. Therefore, since all three sides of an equilateral triangle are equal, all three angles are equal, too.
Are acute triangles always equilateral?
An acute triangle is a triangle in which each angle is an acute angle. All acute triangle angles are less then 90 degrees. For example, an equilateral triangle is always acute, since all angles (which are 60) are all less than 90.
Is a right triangle is never isosceles?
No, not all right triangles are isosceles. Although it is possible to have a right triangle that is an isosceles triangle, not all right triangles…
Is a right triangle always equilateral?
2 Answers By Expert Tutors. A right triangle has one angle of 90º. The sum of the other two angles is 90º (since the sum of the 3 angles is 180º). An equilateral triangle has three equal angles of 60º, so if one angle of a triangle is 90º (that is, it’s a right triangle), then it cannot be an equilateral triangle.
Is a right triangle always acute?
An acute triangle is a triangle in which each angle is an acute angle. Any triangle which is not acute is either a right triangle or an obtuse triangle. All acute triangle angles are less then 90 degrees. For example, an equilateral triangle is always acute, since all angles (which are 60) are all less than 90.
What is the triangle rule?
The Triangle Inequality Theorem states that the sum of any 2 sides of a triangle must be greater than the measure of the third side. In other words, as soon as you know that the sum of 2 sides is less than (or equal to) the measure of a third side, then you know that the sides do not make up a triangle.
Is the equilateral triangle always a regular polygon?
There are other times in which all three legs are of different measures. This is dependent of the measurement of the other two angles. Determine if the statement is always, sometimes or never true. An equilateral triangle is a regular polygon. Always. A regular polygon has all equal sides.
How many degrees does a right triangle have?
All triangles have a total of 180 degrees. A right triangle has one angle that is 90 degrees. How can any other angle equal more than 90 degrees? Right. A right triangle is NEVER an obtuse triangle. Determine if the statement is always, sometimes or never true. A scalene triangle is a regular polygon.
Is the exterior angle of a triangle always 180 degrees?
The measure of an exterior angle at the vertex of a polygon equals the measure of the adjacent interior angle. Sometimes. This happens in the case of squares and rectangles. Determine if the statement is always, sometimes or never true. An exterior angle of a triangle is 180 degrees. Never. This would mean that the interior angle is 0.
What is the sum of all angles of a triangle?
One angle of a triangle is obtuse. The sum of the measures of the other angles must be: Less than 90 degrees. If one angle is obtuse, it measures more than 90 degrees. Thus the other two’s sum must measure less than 90 degrees in order for all three angles to sum to 180 degrees.