You can save and load the formulas to create a formula library. Complex tasks can be explained visually by importing drawings in bitmap format.
RedCrab Homepage RedCrab Plane Geometry
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| fig. 1 Box Volume | fig. 2 Box Surface Area |
| Volume = lwh | Surface Area = 2(lw+lh+wh) |
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Pyramid Information and Reference Several math expressions can be writtenin a row. Between each math expression, there must be a colon. Note. : l = 6: w = 5: h = 4 The expression: c=√((w/2)²+h²): Enter: c = < Ctrl +1 > ((w/2) < Ctrl +2 > + h < Ctrl +2 > ) l = length of base w = width of base h = height of pyramid c and d = slant height of pyramid face (c= length face & d = width face) |
| fig. 3 Pyramid Volume and Surface Area | fig. 4 Pyramid Information & Reference |
| Volume = lwh/3 | Reference: Online Rectangular Pyramid Calculator |
| Surface Area = lc+wd+lw | Reference: Online Rectangular Pyramid Calculator |
| c=√((w/2)²+h²) d=√((l/2)²+h²) | Reference: Online Rectangular Pyramid Calculator |
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Topless Pyramid Information and Reference A trunctated pyramid volume is one third the height times (A + sqrt(A B) + B) where A and B are the area of the top and bottom faces. A= area (AB) and B= area (CD)  RedCrab interprets a sequence of letters, for example, ab, as different variables. Excluding subscript letters, for example XL. Subscript letters always belong to the variable on the left. |
| fig. 5 Topless Pyramid Volume and Surface Area | fig. 6 Topless Pyramid Information & Reference |
| Volume = (h/3)((ab)+(cd)+√((ab)(cd))) | Reference: Online Topless Pyramid calculator |
| Surface Area = x+y+u u=(ab)+(cd) | Reference: Online Geametric shapes Calculator |
| x= 2(a+c)h/2 y= 2(b+d)h/2 | Reference: Online Truncated Pyramid Calculator |
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Cylinder Information and Reference The expression: v = πr²h: Enter: v = < Ctrl + P > r < Ctrl + 2 > h r = radius of cylinder h = height of cylinder Reference: cylinder volume cylinder surface area |
| fig. 7 Cylinder Volume & Surface Area | fig. 8 Cylinder Information & Reference |
| Volume = πr²h | Note: 2πr(r+h) = 2πr² + 2πrh |
| Surface Area = 2πr(r+h) | Reference: cylinder formulas |
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Cone Information and Reference The expression: v = πr²h/3 Enter: v = < Ctrl + P > r < Ctrl + 2 > h/3 r = radius of cone base h = height of cone l = slant height of cone (see diagram) l = √(r²+h²) Total Surface Area = Lateral Surface Area + Base Area Lateral Surface Area = πr√(r²+h²) Base Area = πr² Total Surface Area = πr²+πr√(r²+h²) |
| fig. 9 Cone Volume and Surface Area | fig. 10 Cone Information and Reference |
| Volume = πr²h/3 | Reference: Cone formulas |
| Surface Area = πr²+πR√(R²+h²) | Reference: Cone Calculator |
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Topless Cone Information and Reference L= Lateral Surface Area : A= Total Surface Area V= Volume It is not allowed to split an expression and continue in the next row. Wrong: z= 12+14+15+20 
+5+10Correct: x= 12+14+15+20 z= x+5+10 Topless Cone = Cone Frustum Topless Cone = Truncated Cone |
| fig. 11 Topless Cone Volume | fig. 12 Topless Cone Information & Reference |
| Volume = πh/3(R1²+R2²+R1R2) | Reference: Truncated Cone |
| Surface Area = π(R1+R2)√((R1-R2)²+h²)+π(R1²+R2²) | Reference: Cone Frustum |
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Sphere Information and Reference Error message: For error location RedCrab marks the cell where an error is detected with a blue frame. It also marks the incorrect formula with a red frame.  The expression: v = 4/3πr³: Enter: v = 4/3 < Ctrl + P > r < Ctrl + 3 > r = radius of sphere |
| fig. 13 Sphere Volume and Surface Area | fig. 14 Sphere Information and Reference |
| Volume = 4/3πr³ | Reference: Sphere Calculator |
| Surface Area = 4πR² | Reference: Sphere Calculator |
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Sphere 2 Base Segment Information and Reference You can write several mathematical expressions on one worksheet. The expression result displays only if terminated with an equal sign. Examples: 
a = 27+9 (result a= below)a = 36 a= 27+9 = 36 a = 27+9 (no result shown) a= large radius of segment b= small radius segment h= height of segment R= radius of sphere |
| fig. 15 Sphere 2 base segment Volume and Surface Area | fig. 16 Sphere 2 base segment Information and Reference |
| Volume = (π/3)h²(3R-h) | Reference: Volume of a Spherical Segment |
| Surface Area = 2πRh | Reference: Surface Area of a Spherical Segment |
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Spherical Lune/Wedge Volume and Surface Area A Spherical Lune is the surface area of a Spherical Wedge. θ = angle in degrees  r = radius of sphere The keys < Ctrl + 2> write the exponent 2. The keys < Ctrl + 3> write the exponent 3. The keys < Ctrl + Q> write the Greek letter θ Reference: Sphere formulas Reference: Spherical wedge formulas Reference: Spherical wedge formulas |
| fig 17 Spherical Lune/Wedge Volume and Surface Area | fig 18 Spherical Lune/Wedge Information and Reference |
| Volume Spherical Wedge= (π/270)r³θ | Reference: Volume of a Spherical Wedge in degrees |
| Surface Area Spherical Lune= (π/90)r²θ | Reference: Surface Area of a Spherical Lune in degrees |
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Spherical Cap Information and Reference The expression: A = 2πrh: Enter: A = 2 < Ctrl + P > r h 
Implied multiplication means you do not need to include the multiplication operator.Example: A = 2πrh equals A = 2*π*r*h r = radius of sphere h = height of cap a = radius of cap |
| fig. 19 Spherical Cap Volume and Surface Area | fig. 20 Spherical Cap Information and Reference |
| Volume = πh²(3R-h)/3 | Reference: Spherical Cap Calculator |
| Surface Area = 2πRh | Reference: Spherical Cap |
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Spherical Sector Information and Reference Save: If you are saving a file for the first time, use SaveAs on the File menu, it will prompt you for a file name. If you are saving a changed file, click Save on the file menu  Open: Click Open on the File menu. In the Navigation pane, click on the folder or drive that contains the file that you want to open. You can only load a file that is saved with RedCrab before, with the file extension *.rec. |
| fig. 21 Spherical Sector Volume and Surface Area | fig. 22 Spherical Sector Information and Reference |
| Volume = (2/3)πR²h | Reference: Spherical Sector |
| Surface Area = 2πRh | Reference: Spherical Sector |
