Grade Level(s): 7-8
Introduction: In the early 1400’s, European sailors wanted to trade their goods with the people of the Southern Oceans. When they followed currents and winds they were successful. When confronted with no winds from Central Africa and out into the Atlantic Ocean, they realized that their ships needed to be re-engineered to be able to sail in the shallow waters and high seas. The size and combinations of sails allowed ships to do this, when calm or gale force winds were encountered.
Learner Objectives:
- The student will be able to identify and draw different kinds of triangles: equilateral, right and isosceles.
- The student will be able to define triangles as congruent, and be able to compute the area of triangles.
Florida Sunshine State Standards: Science: SC.H.I.3.5. Math: MA.C.1.3.1
Competency-Based Curriculum: Science: M/J1 I-8-A Math: M/J1 IV-1-A Math: M/J3 III-1-A
Materials:
1 sheet 81/2” X 11” paper per student
colored pencils
protractor
ruler
geoboard
Activity Procedures:
- Students log vocabulary in journal for sail-configuration
- Fold paper in half to create two rectangular polygons
- Fold the two corners (at the fold line) down until they meet. Students open folds and trace lines to create three triangles. Have students measure angles. Discuss right angles and acute angles. Measure sides to show isosceles. Then compare two outer triangles. Students should observe that they are congruent.
- Discuss the area of the rectangle formed by the three triangles, and prove how the center triangle is 1/2 of the rectangle. Discuss formula A= 1/2 (b X H).
- Finish folding paper to make paper sailboat. Again fold paper in half; fold top corners to meet; fold the bottom open edges up, one edge to the back and one to the front; open a little to make sailboat.
- Using geoboards, teacher gives coordinates for students to create triangles with right, acute and obtuse angles. Students also make isosceles, right and equilateral triangles.
Student Assessment:
- Ask students to discuss how the design and shape of the sails affect the movement of a boat.
- In a cooperative manner, ask one student from each group to share their results with the class.
ACTIVITY EXTENSIONS
- Why are currents called Agulhas and Benguela? (Science)
- Where did these terms originate? (History)
Vocabulary: triangle, isosceles, equilateral, right, congruent, leeward, windward, drift, port, starboard
Home Learning Activity:
Find the name of the 2 currents that early traders were confronted with when finding new routes to the Southern Oceans. Chart their flow direction on a map.
REFERENCES/ACTIVITY LINKS:
http://www.boatus.com/onlinecourse/studytopics.html
http://www-personal.umich.edu/~tmorris/boatgen.html
http://ils.unc.edu/maritime/home.html
http://www.amya.org/sailmanual/part2.html
http://www.hoofers.org/sailing/index.html
