I’m using a textbook CGP Math GCSE foundation to answer some questions on geometry,and I came across this question here.As you can there are two shapes shape A is a parallelogram and shape B is a trapezium.For shape A I’m supposed to multiply 10 by 60 which is 60.for shape B there Is no base measurement,so I’m not sure what to do here.Furthermore,everything I have tried will not result in 82.5cm as that’s what it says in answer sheet.Could someone explain to me what I have done wrong.
I’m not sure how to work out the area of this composite shape
- Thread starter Osman123
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For the parallelogram we have:
[MATH]A_P=bh=(10\text{ cm})(6\text{ cm})=60\text{ cm}^2[/MATH]
For the trapezium we have:
[MATH]A_T=\frac{1}{2}(B+b)h=\frac{1}{2}(10\text{ cm}+5\text{ cm})(3\text{ cm})=\frac{45}{2}\text{ cm}^2[/MATH]
And so the total area is:
[MATH]A=A_P+A_T=60\text{ cm}^2+\frac{45}{2}\text{ cm}^2=\frac{165}{2}\text{ cm}^2=82.5\text{ cm}^2[/MATH]
[MATH]A_P=bh=(10\text{ cm})(6\text{ cm})=60\text{ cm}^2[/MATH]
For the trapezium we have:
[MATH]A_T=\frac{1}{2}(B+b)h=\frac{1}{2}(10\text{ cm}+5\text{ cm})(3\text{ cm})=\frac{45}{2}\text{ cm}^2[/MATH]
And so the total area is:
[MATH]A=A_P+A_T=60\text{ cm}^2+\frac{45}{2}\text{ cm}^2=\frac{165}{2}\text{ cm}^2=82.5\text{ cm}^2[/MATH]
HallsofIvy
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You say "for shape B there Is no base measurement,so I’m not sure what to do here."
The base of B is the same as the base and top of A which are given as 10 cm.
The base of B is the same as the base and top of A which are given as 10 cm.
