Unit 1, Lesson 8

Area of Triangles

Grade 6

Practice

1. Problem 1

   Student Task Statement

   To find the area of this right triangle, Diego and Jada used different strategies. Diego drew a line through the midpoints of the two longer sides, which decomposes the triangle into a trapezoid and a smaller triangle. He then rearranged the two shapes into a parallelogram.

   

   A triangle with one side labeled 3 feet and another side labeled 8 feet. A second image displays the same triangle with a dashed line bisecting the triangle so the side that was labeled 8 feet is now two pieces, each labeled 4 feet. An arrow indicates that the resulting smaller portion is rotated to create a parallelogram with a base of 3 feet and a height of 4 feet.

   Jada made a copy of the triangle, rotated it, and lined it up against one side of the original triangle so that the two triangles make a parallelogram.

   

   1. Explain how Diego might use his parallelogram to find the area of the triangle.
   2. Explain how Jada might use her parallelogram to find the area of the triangle.