A right triangle has to have a right angle, which is equal to

This is an equilateral triangle because the sides are all equal, and an equilateral triangle has to have all sides equal in length.

This triangle is not a scalene triangle because all of the side lengths are not different lengths.

This is not an isosceles triangle because an isosceles triangle has only two equal sides.

This is not a right triangle because a right triangle has to have a right angle, an angle that measures .

The two-dimensional shape in the image is a heptagon. A heptagon has seven sides, seven angles, and seven vertices. The sum of the interior angles is 900°.

This is an isosceles triangle because an isosceles triangle has two equal sides.

This triangle is a not scalene triangle because a scalene triangle has side lengths of all different lengths.

This is not an equilateral triangle because an equilateral triangle has to have all sides equal in length.

This is not a right triangle because a right triangle has to have a right angle, an angle that measures .

This triangle is a scalene triangle because all of the side lengths are different lengths.

This is not an equilateral triangle because an equilateral triangle has to have all sides equal in length.

This is not an isosceles triangle because an isosceles triangle has two equal sides.

This is not a right triangle because a right triangle has to have a right angle, an angle that measures .

This is a right triangle because a right triangle has to have a right angle, an angle that measures . The angle on the top right is a angle.

This is not an equilateral triangle because an equilateral triangle has to have all sides equal in length, and no right angles.

This is not an isosceles triangle because an isosceles triangle has two equal sides.

The two-dimensional figure shown in the image is a pentagon. A pentagon is classified by having five sides, five angles, and five vertices. A pentagon has interior angles that add to 540 degrees. Regular pentagons have sides of equal length and interior angles of 108 degrees.

This is a right triangle because a right triangle has to have a right angle, an angle that measures . The angle on the top left is a angle.

This is not an equilateral triangle because an equilateral triangle has to have all sides equal in length, and no right angles.

This is not an isosceles triangle because an isosceles triangle has two equal sides.

The two-dimensional figure in the question is a quadrilateral. A quadrilateral is a four-sided shape, has four angles and four vertices. More specifically, this type of quadrilateral can be called a trapezoid or parallelogram.

This is a right triangle because a right triangle has to have a right angle, an angle that measures . The angle on the far right is a angle.

This is not an equilateral triangle because an equilateral triangle has to have all sides equal in length, and no right angles.

This is not an isosceles triangle because an isosceles triangle has two equal sides.