Olympiad Test: Perimeter and Area - 1 - Class 7 MCQ

The area of a triangle is given by the formula: (1/2) × base × height

we know that:

 area=(1/2) × base × height
so, height=(2×area)/base

Area of triangle= ½ x base x height
=½x4x3=6cm²

The total area of the wall can be calculated by subtracting the area of the door from the total area of the wall.

The area of the wall is 11×11=121m².

The area of the door is 4m×5m=20m².

Therefore, the remaining area to be painted is (121−20)m² =101m².

Now, multiply the remaining area by the labor charges per square meter to find the total labor charges:

Total labor charges=Area to be painted×Labor charges per square meter

Total labor charges=101m²×Rs 2.50/m²

Total labor charges=Rs 252.50

So, the total labor charges for painting the wall would be Rs 252.50.

use the formula of circumference: 2πr

given: diameter=2r=10cm

so, circumference 2πr=(3.14)10=31.4 cm

The formula for the area of a rectangle is given by:

Area=Length×Breadth

In this case, the area is given as 440 m² and the length is given as 22 m. Let's denote the breadth as B. The formula can be rearranged to solve for the breadth:

Breadth=Area/Length

Substitute the given values:

Breadth=440 m²/22 m

Breadth=20 m

perimeter is the distance around a given two-dimensional object.

The correct answer is A:

When a square is cut along one of its diagonals, it forms two congruent right-angled triangles. Each of these triangles has a base and height equal to one of the sides of the square. The area of a triangle is given by the formula:

Area of a triangle=(1/2)×base×height

In this case, the base and height of each triangle are the sides of the square. Therefore, the area of each triangle is:

Area of each triangle=(1/2)×side×side

Since the side of the square is the length of the diagonal, we can write the area of each triangle as:

Area of each triangle=(1/2)×diagonal×diagonal

So, the correct option is A: (1/2)×Area of the square.

Area of Rectangle = length of rectangle x breadth of rectangle. Therefore, Area of Rectangle/breadth of rectangle = length of rectangle.

Perimeter of a rectangle = 2 x (Length + Width)

Given: Length = 12 meters Width = 8 meters

Perimeter = 2 x (12 meters + 8 meters) Perimeter = 2 x (20 meters) Perimeter = 40 meters

So, the perimeter of the garden is 40 meters.