Triangles and Parallelograms Lesson 11.2
Theorem 100: The area of a parallelogram is equal to the product of the base and the height. A = bh h b M T H 13cm 9cm 6cm A Find the area of MATH
M T H 13cm 9cm 6cm A You will receive one point for each line, plus the correct unit. Minimum 3 lines. A = bh = 13(6) = 78cm2
Theorem 101: The area of a triangle is equal to one-half the product of a base and the height (or altitude) for that base. A = bh Where b is the length of the base and h is the altitude. Altitude may be inside, outside or the leg of the triangle. The base may not always be at the bottom. h b
Find the area of this triangle. 12mm 8mm A = 48 mm2 x 15 Find the base of a triangle with an altitude of 15 and area 60. x = 8
How will you find the height? Find the area of a parallelogram whose sides are 14 and 6 and whose acute angle is 60˚. Draw and label. D 6 14 60˚ U C K 6 How will you find the height?
Drop line DS to form a 30-60-90 triangle. Line DS is 14 60˚ U C K S Drop line DS to form a 30-60-90 triangle. Line DS is A = bh = 14( ) = 42
Team Activity: Draw a parallelogram that has a perimeter of 40 units . What is its area? Which team created the parallelogram with the GREATEST area? What shape is it?