Lesson 5.25.2 Small Group · Group 1
Group 1 · Set BSecond form · new problems, same idea
Learning target With my small group, I can find the area of a triangle using the formula A = ½ × base × height — one step at a time, with support.
Remember5.2 Small Group · Group 1
To find the area of a triangle, multiply the base by the height, then take half, because a triangle is half of a rectangle. A triangle is half of a rectangle. So its area is half of the base times the height.
Words: Base (Base)Height (Altura)Area (Área)Perpendicular (Perpendicular)Composite figure (Figura compuesta)
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1Complete each step, then write the final answer.
A triangle has a base of 8 inches and a height of 5 inches. Find its area.
Show your workHint First multiply 8 × 5. Then take half.
Final answer: -
2Complete each step, then write the final answer.
A triangle has a base of 12 cm and a height of 5 cm. Find its area.
Show your workHint Multiply the base by the height. Then take half.
Final answer: -
3Complete each step, then write the final answer.
The front of a tent is a triangle. It is 8 feet wide at the bottom and 6 feet tall. What is the area of the tent front?
Show your workHint The width at the bottom is the base. How tall it is is the height.
Final answer: -
4Complete each step, then write the final answer.
The front of a cabin is a triangle. Its base is 10 feet. Its height is 6.5 feet. Find the area of the cabin front.
Show your workHint Multiply 10 × 6.5 first. Then take half of the product.
Final answer:
Explain your thinkingWhy do we take half of base × height for a triangle? Use Sam’s mistake to explain.
Sentence starter Base × height gives the area of a ___. · The triangle is half because ___.