Geometry: Areas of parallelograms Chapter 9.1A Geometry: Areas of parallelograms

What is a parallelogram? Parallelograms look like rectangles that are falling over (actually rectangles and squares technically ARE parallelograms, just with special names!)

Area of a parallelogram Parallelograms have the same formula for AREA as rectangles and squares. A = b x h H E I G T BASE H E I G T The height is perpendicular to the base, NOT the slanted line!!! BASE

Some heights are outside the shape, so be careful! 4.2 in 7 in. 6 in. 7.3 in. 8 in. ALWAYS write the formula, then plug in the numbers! A = b x h A = 4.2 x 7.3 A = b x h A = 8 x 6 A = 30.66 in2 A = 48 in2 Area is always labeled in “square” measures

Why Square Units? Height = 4 units Base = 8 units Square units means how many squares fit INSIDE the shape! Height = 4 units Base = 8 units

Working backwards A = b x h 96 = 12 x h A = 96 ft2 h Since we know the AREA already, work the problem backwards to find the height! A = b x h 96 = 12 x h h = 8 ft. 96 ÷ 12