Rect.height  

var rect = Rect (0, 0, 10, 10);
print(rect.height);
rect.height = 20;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Rect rect = new Rect(0, 0, 10, 10);
    void Example() {
        print(rect.height);
        rect.height = 20;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public rect as Rect = Rect(0, 0, 10, 10)

    def Example():
        print(rect.height)
        rect.height = 20