How to find Area

Including Squares, Rectangles, Triangles, and Trapezoids

Area of a Square and a Rectangle

Since a square has all the same sides the area will be pretty easy. All you need to do is multiply the bottom line (base) and the side line (height). In a question there might be only one side length if your finding the area for a square. The easier way of saying it is base times height, the formula is A=bxh. The rectangle has the same formula for a square, thats why didn't go in detail for area of a rectangle. For a rectangle there will be 2 side lengths for the question.

Area for a Triangle

A triangle is half of a square, and you should find the area like you would do with a square. If you see a line in the middle thats the height, and same as the square you multiply the base times the height. Here is when you do something different, you divide the product by 2, and the quotient is the area of the triangle.

The formula is A=bxh1/2

Area for a Trapezoid

Trapezoid is a bit more complicated than the area for a square, and a triangle. It is more complicated because there are more steps that you have to take to get the area. You get both of the bases (the two horizantal lines) and you add them. Then you do take the sum of the lines and you multiply it by the height, the product of the both lengths will be divided by 2. The formula is A=hx(b1+b2)1/2

STAAR Queston

Here is your moment to see if you mastered the area.

1. What is the area of a square with the base of 12?

2. What is the area of a triangle with the a base of 5 and a height of 2?

3. What is the area of a trapezoid with 2 bases lengths of 4 and 5 and a heighth of 2?


Pictures: Goggle images

Info: 7th grade On-Level Math Journal

Flyer made by: Ayrton Meza