Does anyone know the formulas for area for these shapes?
I’m having trouble remembering the formulas to find area for the following shapes. Can anyone help me out?
area of a pentagon
Trapezoid
right trapezoid
Regular Hexagon
Thanks!
Also, I’m pretty sure that the formula for volume for all prisms is Area of the base * the height. Is that right?
volume for all prisms is Area of the base * the height
area of a pyramid = 1/3 * base * height.
Trapezoid (B+b) * h/2
right trapezoid same
Regular Hexagon is 6 triangles. height of each = (s^2-(s/2)^2)^.5 then for s=2, (4-1)^.5
or, 1/2 * s *s *3^.5
so for the hexagon, it’s 6 * 1/2 * s *s *3^.5 = 3s^2*3^.5
pentagon
The area of any regular polygon is A=(1/2)(apothem)(perimeter).
The area of a trapezoid is A=(1/2)(h)(a+b), where a and b are the parallel sides.
And yes, the volume of a prism is area of the base x height.
References :
volume for all prisms is Area of the base * the height
area of a pyramid = 1/3 * base * height.
Trapezoid (B+b) * h/2
right trapezoid same
Regular Hexagon is 6 triangles. height of each = (s^2-(s/2)^2)^.5 then for s=2, (4-1)^.5
or, 1/2 * s *s *3^.5
so for the hexagon, it’s 6 * 1/2 * s *s *3^.5 = 3s^2*3^.5
pentagon
References :
I know for a trapezoid is (b1+b2/2)h. This means the length of the top line + the length of the bottom line divided by 2. Times the height
References :
You having trouble with the area? Let me help you:
Trapezoid – A=h * 1/2(b1 =+b2)
Pentagon, Hexagon – I’m sorry but I don’t know those, but I do know some others…
parallelogram – Area: b*h
rectangular prism – surface: 2wl+2wh+2wl volume:l*w*h
cylinder – surface: 2 pi r* h + 2 pi r(the r is squared), volume: pi r (r is squared) h
sphere – surface: 4 pi r (r is squared) volume: 4/3(pi r ( r is cubed)
cone- surface: pi r ( r is squared)+pi rl volume:1/3(pi r(r is squared) h
pyramid – volume: 1/3(a*b)h
And No, area for all prisims are noy always B*H. and sorry that i couldn’t find the area for the hexagon and the pentagon.
Hope I helped!
References :