Page 147 - NUMINO TG_6A
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Challenge A Cow Outside the Fence
jOb ective Solve challenge problems by solving for area.
1. Textbook Instructions Challenge A Cow Outside the Fence
Students will have to use their problem Students will have to use their problem solving skills to solve the following problems.
solving skills to solve the following problems. Have them look at the example carefully before moving on to the problems.
Have them look at the example carefully
before moving on to the problems. A cow is tied to a fence by a 3 m-long rope. The cow cannot go inside the
fence. What is the area of the land that the cow can move around?
The problem is asking for the area that a cow
that is tied to a fence can move around in. 4m
The place where the cow is tied is the center
of the circle and the rope is the length of the 2m
radius. Draw a diagram to solve.
Since the rope is 3 m, the 3m
cow can move in the
space shown. Since the rope is 3 m long, it will reach over the corner of the side of the fence by 1 m.
This creates another area of a quarter circle with a radius of 1 m that the cow can move around.
Since the rope is 3 m 1m
long, it will reach over the 2m Area of the semicircle
corner of the side of the 3m
3.14 3 3 1 14.13 (m2)
2
1m
fence by 1 m. This creates 1m 2m The radius of the quarter circle is
3m 4m
another area of a quarter circle with a 3 2 = 1(m).
1m
Area of the 2 quarter circles
radius of 1 m that the cow can move (3.14 1 1 1 ) 2 1.57 (m2)
4
around in.
The answer can be found by finding the Area of the semicircle Area of the
sum of the areas of the red and yellow 2 quarter circles.
figures.
14.13 1.57 15.7 (m2)
80
2. Build Understanding
Draw a diagram to solve
1a. The lamb can move in the area shown by the shaded part in the
diagram. The colored part is 3 of a circle whose radius if 5 m. Find the area 6m
4
of 3 of the circle.
4
5m
Area of 3 of the circle 3.14 5 5 3
4 4
3
78.5 4
58.875 (m2)
130 NUMINO Teacher s Guide
jOb ective Solve challenge problems by solving for area.
1. Textbook Instructions Challenge A Cow Outside the Fence
Students will have to use their problem Students will have to use their problem solving skills to solve the following problems.
solving skills to solve the following problems. Have them look at the example carefully before moving on to the problems.
Have them look at the example carefully
before moving on to the problems. A cow is tied to a fence by a 3 m-long rope. The cow cannot go inside the
fence. What is the area of the land that the cow can move around?
The problem is asking for the area that a cow
that is tied to a fence can move around in. 4m
The place where the cow is tied is the center
of the circle and the rope is the length of the 2m
radius. Draw a diagram to solve.
Since the rope is 3 m, the 3m
cow can move in the
space shown. Since the rope is 3 m long, it will reach over the corner of the side of the fence by 1 m.
This creates another area of a quarter circle with a radius of 1 m that the cow can move around.
Since the rope is 3 m 1m
long, it will reach over the 2m Area of the semicircle
corner of the side of the 3m
3.14 3 3 1 14.13 (m2)
2
1m
fence by 1 m. This creates 1m 2m The radius of the quarter circle is
3m 4m
another area of a quarter circle with a 3 2 = 1(m).
1m
Area of the 2 quarter circles
radius of 1 m that the cow can move (3.14 1 1 1 ) 2 1.57 (m2)
4
around in.
The answer can be found by finding the Area of the semicircle Area of the
sum of the areas of the red and yellow 2 quarter circles.
figures.
14.13 1.57 15.7 (m2)
80
2. Build Understanding
Draw a diagram to solve
1a. The lamb can move in the area shown by the shaded part in the
diagram. The colored part is 3 of a circle whose radius if 5 m. Find the area 6m
4
of 3 of the circle.
4
5m
Area of 3 of the circle 3.14 5 5 3
4 4
3
78.5 4
58.875 (m2)
130 NUMINO Teacher s Guide
