Follow a worked example.
Every example below can be loaded using its calculator’s Reset example button. Inputs use centimetres, square centimetres or cubic centimetres as labelled, while angles use degrees.
Base and perpendicular height
Given: Base b = 8; Height h = 5.
A = bh
| Measurement | Calculated value |
|---|---|
| Area | 40 cm² |
Sides and included angle
Given: Side a = 8; Side b = 5; Included angle θ = 60.
A = ab sin θ; P = 2(a+b)
| Measurement | Calculated value |
|---|---|
| Area | 34.641016 cm² |
| Perimeter | 26 cm |
| Height to a | 4.330127 cm |
| Diagonal 1 | 11.357817 cm |
| Diagonal 2 | 7 cm |
Diagonals and crossing angle
Given: Diagonal p = 10; Diagonal q = 8; Crossing angle θ = 60.
A = pq sin θ/2
| Measurement | Calculated value |
|---|---|
| Area | 34.641016 cm² |
Area to perpendicular height
Given: Area A = 40; Base b = 8.
h = A/b
| Measurement | Calculated value |
|---|---|
| Perpendicular height | 5 cm |
Check the answer’s dimensions
An area contains a product of two lengths, while volume contains three. A perimeter or radius is still a length. If your input measurements are mixed between metres and centimetres, convert them to a common unit first. A realistic-looking number can still be wrong if the units were inconsistent.