Как сделать чтобы элементы внутри окна при растягивании экрана тоже растягивались, используя при этом Tab Widget?

Код:

import sys
from PyQt5 import QtCore, QtWidgets
from PyQt5.Qt import *

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(713, 522)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
        self.tabWidget.setObjectName("tabWidget")

        #self.tab = QtWidgets.QWidget()
        self.tab = Tab_1Widget()

        self.tab.setObjectName("tab")
        self.groupBox = QtWidgets.QGroupBox(self.tab)
        self.groupBox.setGeometry(QtCore.QRect(0, 380, 120, 80))
        self.groupBox.setStyleSheet("background-color: rgb(85, 170, 127);")
        self.groupBox.setObjectName("groupBox")
        self.label = QtWidgets.QLabel(self.groupBox)
        self.label.setGeometry(QtCore.QRect(30, 30, 47, 13))
        self.label.setObjectName("label")
        self.groupBox_2 = QtWidgets.QGroupBox(self.tab)
        self.groupBox_2.setGeometry(QtCore.QRect(0, 0, 691, 91))
        self.groupBox_2.setStyleSheet("background-color: rgb(85, 170, 127);")
        self.groupBox_2.setTitle("")
        self.groupBox_2.setObjectName("groupBox_2")
        self.label_2 = QtWidgets.QLabel(self.groupBox_2)
        self.label_2.setGeometry(QtCore.QRect(40, 30, 47, 13))
        self.label_2.setObjectName("label_2")
        self.lineEdit = QtWidgets.QLineEdit(self.groupBox_2)
        self.lineEdit.setGeometry(QtCore.QRect(100, 30, 113, 20))
        self.lineEdit.setObjectName("lineEdit")
        self.pushButton = QtWidgets.QPushButton(self.groupBox_2)
        self.pushButton.setGeometry(QtCore.QRect(540, 30, 75, 23))
        self.pushButton.setStyleSheet("")
        self.pushButton.setObjectName("pushButton")
        self.tabWidget.addTab(self.tab, "")
        self.tab_2 = QtWidgets.QWidget()
        self.tab_2.setObjectName("tab_2")
        self.groupBox_4 = QtWidgets.QGroupBox(self.tab_2)
        self.groupBox_4.setGeometry(QtCore.QRect(0, 0, 691, 461))
        self.groupBox_4.setStyleSheet("background-color: rgb(85, 170, 127);")
        self.groupBox_4.setTitle("")
        self.groupBox_4.setObjectName("groupBox_4")
        self.label_4 = QtWidgets.QLabel(self.groupBox_4)
        self.label_4.setGeometry(QtCore.QRect(290, 40, 101, 16))
        self.label_4.setObjectName("label_4")
        self.label_3 = QtWidgets.QLabel(self.groupBox_4)
        self.label_3.setGeometry(QtCore.QRect(90, 200, 47, 13))
        self.label_3.setObjectName("label_3")
        self.label_5 = QtWidgets.QLabel(self.groupBox_4)
        self.label_5.setGeometry(QtCore.QRect(320, 200, 47, 13))
        self.label_5.setObjectName("label_5")
        self.label_6 = QtWidgets.QLabel(self.groupBox_4)
        self.label_6.setGeometry(QtCore.QRect(550, 200, 47, 13))
        self.label_6.setObjectName("label_6")
        self.tabWidget.addTab(self.tab_2, "")
        self.gridLayout.addWidget(self.tabWidget, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.tabWidget.setCurrentIndex(0)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.groupBox.setTitle(_translate("MainWindow", "GroupBox"))
        self.label.setText(_translate("MainWindow", "TextLabel"))
        self.label_2.setText(_translate("MainWindow", "Введите:"))
        self.pushButton.setText(_translate("MainWindow", "PushButton"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Tab 1"))
        self.label_4.setText(_translate("MainWindow", "Основная надпись"))
        self.label_3.setText(_translate("MainWindow", "TextLabel"))
        self.label_5.setText(_translate("MainWindow", "TextLabel"))
        self.label_6.setText(_translate("MainWindow", "TextLabel"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Tab 2"))

class Tab_1Widget(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()

        self.flag = False
        self.c = 0
        self.b = 0

    def paintEvent(self, e):
        if self.flag:
            qp = QPainter()
            qp.begin(self)
            self.drawRectangles(qp)
            qp.end()

    def drawRectangles(self, qp):
        qp.drawRect(10, 160, self.c, self.b)

class Example(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):
        super().__init__()
        self.setupUi(self)

        self.pushButton.clicked.connect(self.onClicked)

    def onClicked(self):
        self.tab.flag = True
        try:
            a = int(self.lineEdit.text())
        except: pass
        else:
            b = a * 2
            c = a + b
            self.tab.c = c
            self.tab.b = b
            self.update()

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    w = Example()
    w.show()
    sys.exit(app.exec_())