Unit 1 Day 1

Day 1: Finding the area of basic shapes

 

Square: To find the area of a square, multiple base x height.  For example, a square with a height of 5 feet would have 25 feet squared of area.

Rectangle: To find the area of a rectangle, you also multiply length x width. For example if the base was 10 and the height was 2, the area would be 20 feet squared.

Triangle: To find the area of a triangle, you use the equation base x height divided by 2. For example, if the base was 5 and the height 6, the area would be 15 feet squared. 

Trapezoids: To find the area of a trapezoid, you take the sum of the 2 bases, multiply it by the height, and divide by 2. For example, if base 1= 5in and base 2= 10in, and the height= 5in, the area would be 37.5 inches squared. 

Parallelograms: Parallelograms may look complicated, but you just have to use the same equation as for a square: base x height. 

Circles: To find the area of a circle, you use the equation πr², with r meaning radius.

Polygons: A polygon is a shape with at least 3 sides and angles. For our purposes, it'll be pentagons and octagons, but this can be applied to almost any shape. For its area, you take the apothem (the distance from the center to an outside edge), the length of a side, and the number of sides. Then you use the equation 1/2nsr (number of sides, side length, apothem).For example, if the apothem were 5, it was a pentagon, and the length of each side was 5, you would get 62.5².

Definitions:

Point: The definite position on a graph to indicate position or direction.

Line: A long thin mark made on the surface

Plane: a flat or level surface

Line Segment: The finite section of a line

Ray: a line outward from the center

Angle: The space between converging lines or surfaces

Median: The middle number or point

Altitude: The height of a thing above the reference point

Perpendicular:Meeting a given line at right angles

 

 

Quiz Time!

 

1. What is the area of this  circle given the diameter is 12 inches?

 

2. What is the formula for area of a polygon?

 

3. What is the area of this trapezoid?

 

 

 

 

 

 

 

 

 

Key

 

1. The area of the circle is 113.04 inches². To get this I multiplied pi by the square of 6, which is 36.

 

2. The formula for the area of a polygon is (1/2)nsr.

 

3. The area of this trapezoid is 18 meters², which I got by adding 3 and 6 (9), multiplying it by 4 (36) and dividing it in half.