Lesson 5.45.4 Small Group · Group 2
Group 2 · Set BSecond challenge form · new problems, same idea
Learning target I can find the area of a composite figure by decomposing it into basic shapes, including a regular polygon split into triangles, and adding or subtracting the areas, explain why the method works, and use it on a problem I have not seen before.
Remember5.4 Small Group · Group 2
A composite area can be found by adding joined pieces or by subtracting a cut-out from a bigger shape, and both ways must agree. Some composite figures hide side lengths. Find the missing sides first, then add pieces or subtract a cut-out.
Words: Composite Figure (Figura compuesta)Decompose (Descomponer)Add (Sumar)Subtract (Restar)Formula (Fórmula)
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1Complete each step, then write the final answer.
A rectangular deck is 10 m by 8 m. A 4 m by 3 m hot tub is cut out of one corner. What is the area of the deck?
Show your workFinal answer: -
2Complete each step, then write the final answer.
An L-shape fits in a 9 cm by 7 cm rectangle. A 3 cm by 2 cm corner is cut out. Find the area of the L-shape.
Show your workFinal answer: -
3Complete each step, then write the final answer.
A window is a regular octagon. It splits into 8 congruent triangles. Each has a base of 10 inches and a height of 12 inches. Find the area of the window.
Show your workFinal answer: -
4Complete each step, then write the final answer.
A square tile is 12 cm on each side. A triangle is cut from each of its 4 corners. Each triangle has a base of 3 cm and a height of 3 cm. What area is left?
Show your workFinal answer: