A triangle is drawn without reference to a coordinate system. The bottom of the triangle is horizontal, and the other two sides are diagonal, with the upper vertex positioned about two thirds of the way from left to right.
The right diagonal is labeled \(a\text{,}\) the bottom is labeled \(b\text{,}\) and the left diagonal is labeled \(c\text{.}\) A dashed line is drawn from the upper vertex to the bottom, which it meets at a right angle. This line is the altitude of the triangle, and it is labeled \(h\text{,}\) for height. The angle at the bottom-right vertex of the triangle is labeled \(\theta\text{.}\)
A right circular cone is drawn without reference to a coordinate system. The apex of the cone is at the top, and the circular base is at the bottom. A dashed line from the center of the base to the edge is labeled \(r\text{,}\) for radius. Another dashed line from the center of the base to the apex is labeled \(h\text{,}\) for height.
A parallelogram is drawn without reference to a coordinate system. The top and bottom sides are horizontal, while the left and right sides are diagonal, with positive slope. The bottom side of the parallelogram is labeled \(b\text{,}\) for base.
A dashed line is drawn from the top-left vertex to the base, which it meets at a right angle. This line is labeled \(h\text{,}\) for the height of the parallelogram.
A generic right circular cylinder is drawn without reference to a coordinate system. The cylinder is oriented vertically, with a circular base at the bottom.
One side of the cylinder is labeled \(h\text{,}\) for the height, and a line segment is drawn from the center of the circular top to the edge, and labeled \(r\text{,}\) for radius.
The top side is shorter, and labeled with its length, \(a\text{.}\) The longer bottom side is labeled with the length \(b\text{.}\) The other two sides are slanted.
A dashed line is drawn from the top-left vertex to the base, perpendicular to the two parallel sides. This line is labeled \(h\text{,}\) for the height of the trapezoid.
A sphere is drawn without reference to a coordinate system. A line from the center of the sphere to its right edge is labeled \(r\text{,}\) for the radius. A great circle is drawn around the middle of the sphere, corresponding to what would be the equator on Earth.
A simple sketch of a circle, without reference to coordinates. A line segment from the center of the circle to the circumference indicates the radius, \(r\text{.}\)
A drawing of a sector of a circle, without reference to a coordinate system. The sector is shaped like a slice of pie, corresponding to an acute angle. The angle is labeled \(\theta\text{,}\) and the line segment on one side of the angle is labeled \(r\text{,}\) for the radius. The circular arc opposite the angle is labeled \(s\text{,}\) for its arc length.
A drawing of a general right cylinder without reference to a coordinate system. The base of the cylinder is a general plane region bounded by a simple, closed curve. The base is labeled with its area, \(A\text{.}\) The sides of the cylinder are vertical, and labeled with a height, \(h\text{.}\) The top of the cylinder is another copy of the base.
