Lesson 3

Sink and Float

Est. Class Sessions: 3

Daily Practice and Problems

Teacher Notes
X

TIMS Task

12 cm. To find the area of a triangle you multiply the base × height and then multiply this by 1/2. So, 15 × n × 1/2 = 90. To solve this, I thought that since a triangle is half of a rectangle I could double the area to 180 and then find 180 × 1/2 = 90. 15 × 12 = 180. So the base is 12 cm.

L. Geometry Riddle

The height of one side of a right triangle is 15 cm.

The area of the triangle is 90 sq cm.

What is the length of the base of this triangle? Explain how you solved this.