Objectives

• Recognize the area of a triangle as half the area of a related parallelogram.
• Find the area of triangles given base and height.
• Find unknown dimensions of triangles given area and another dimension.
• Find areas of combined figures involving triangles.

Vocabulary

Triangle

a polygon with three sides.

Parallelogram

a four sided figure with opposite sides congruent and parallel.

Rectangle

a parallelogram with opposite sides congruent and parallel and with four right angles.

Square

a parallelogram with four congruent, parallel sides and four congruent right angles.