Lesson 1: Determine the Area of Parallelograms and Rhombuses6.GR.1

I can…

I can find the area of a parallelogram using base × height.

Key words

• Area of Parallelograms — The space inside a parallelogram. Formula: A = b × h, using the perpendicular height.
• Slanted side — A side that leans instead of going straight up and down. It is not the perpendicular height.
• Parallelogram — A four-sided shape with two pairs of parallel sides.
• Parallel — Two lines or sides that stay the same distance apart and never meet.
• Base — Any side of a parallelogram can be the base. Once you pick a base, the height must be measured perpendicular (at a 90° angle) to it.
• Height — The straight-up distance from the base to the top.
• Perpendicular — Two lines that meet to make a square corner (90 degrees).
• Area — How much space is inside a flat shape.
• Composite figure — A shape made by putting two or more simple shapes together.
• Formula — A math rule written with symbols.

Steps

1. I have a parallelogram with a base of 14 feet and a height of 9 feet.
2. I write the formula: A = base × height.
3. I put in the numbers: A = 14 × 9.
4. I multiply: 14 × 9 = 126.
5. So the area is 126 square feet. I used the height of 9, not the slanted side.

Try it

A parallelogram has a base of 13 inches and a height of 5 inches. What is its area?

Check your answer

65 sq in

A = b x h = 13 x 5 = 65 square inches.

Sentence starter

I know ___ because ___.

Goal: I can explain how I found the area using the words base, height, area, and formula.