# Pythagoras

> A right triangle with legs a and b and a square on each side, each drawn with its own squares_enter and labeled with its area (a² = 9, b² = 16, c² = 25).…

Page: https://fframes-kit.pages.dev/docs/math/pythagoras/
Cargo feature: `math` (`fframes-kit = { version = "..", features = ["math"] }`)

A right triangle with legs `a` and `b` and a square on each side, each drawn with its own
`squares_enter` and labeled with its area (`a² = 9`, `b² = 16`, `c² = 25`). `corner` is the
right angle. Gallery scene: `Pythagoras`, drawn at 70 pixels per unit.

Gallery clip of `Pythagoras`: https://fframes-kit.pages.dev/media/scenes/Pythagoras-e59be004.mp4

```rust
use fframes_kit::prelude::*;

fn figure<'a>(ui: &mut Ui<'a, '_, '_>) -> Svgr<'a> {
    let create = |delay| Some(EnterAnim::from(Create { delay, ..Create::default() }));
    let mut small = ui.with_space(Space { origin: (960.0, 560.0), unit: 70.0 });
    small.show(Pythagoras {
        corner: (-1.5, -2.4),
        squares_enter: [create(0.6), create(1.2), create(1.8)],
        ..ui.defaults()
    })
}

assert_eq!(Pythagoras::default().areas(), [9.0, 16.0, 25.0]);
```

## API

Components are plain structs. Set the fields you need and fill the rest with `..ui.defaults()`: the defaults below come from the current theme (`theme.` values are fields of `Theme`).

### Pythagoras

| Field | Type | Default | Description |
| --- | --- | --- | --- |
| `a` | `f64` | `3.0` | Length of the leg along the x-axis, in units of `ui.space`. |
| `b` | `f64` | `4.0` | Length of the leg going up, in units of `ui.space`. |
| `corner` | `(f64, f64)` | `(0.0, 0.0)` | The right angle's position, in units of `ui.space` (y up). |
| `labels` | `bool` | `true` | Shows each square's area at its centre when `true`. |
| `triangle_color` | `Color` | `theme.colors.title` | Colour of the triangle. |
| `colors` | `[Color; 3]` | `[theme.colors.accent, theme.colors.highlight, theme.colors.caption]` | The squares on `a`, `b` and the hypotenuse. |
| `stroke_width` | `f32` | `theme.stroke.regular` | Outline width in pixels of the triangle and squares. |
| `enter` | `Option<EnterAnim>` | `None` | How the triangle appears; `None` shows it from the start. |
| `squares_enter` | `[Option<EnterAnim>; 3]` | `[None, None, None]` | How each of the squares on `a`, `b` and the hypotenuse appears; `None` shows it from the start. |
| `labels_enter` | `Option<FadeIn>` | `None` | Fade in of the area labels; `None` for none. |

Methods:

- `fn areas(&self) -> [f64; 3]`: The squares' areas: `a²`, `b²` and `c²`.

Feature `math` · [Source](https://github.com/khanhthanhdev/fframes-kit/blob/main/fframes-kit/src/kits/math/pythagoras.rs#L21)