Angles in Shapes

The content of Shapes and Angle Class 5 contains the description of different angles in shape. Here students will learn about equilateral triangle angles.

In this learning concept, the students will also learn to

Classify scalene triangle angles.
Identify how many angles are there in a triangle.
Evaluate how many right angles are in a triangle.

Each concept is explained to class 5 maths students using illustrations, examples, and mind maps. Students can assess their learning by solving the two printable worksheets given at the page’s end.

Download the class 5 maths shapes and angles worksheet and check the solutions to the shapes and angle question for class 5 provided in PDF format.

Every object around us has a specific shape.
The shape is classified into two types: Open shape and Closed shape.
The shape in which the starting and the ending point are not the same is called the open shape. An open shape has space between them.
The shape in which the starting and the ending point are the same is called the closed shape. A closed shape has no space between them.
A circle is a closed shape.
A semi-circle is an open shape.
The angle inside the shape is called the interior angle of a shape.

How Many Angles Are There in a Triangle?

A triangle is three sides bounded figure.
It has three interior angles.
Sum of the interior angle of the triangle is 180°.

The three-interior angle of the triangle is ∠A, ∠B, and ∠C. ∠A + ∠B + ∠C = 180°.

Equilateral Triangles Angles:

A triangle in which all the interior angles are equal to 60° is called an equilateral triangle.

Isosceles Triangle Angles:

A triangle in which two interior angles are equal is called an isosceles triangle.

Scalene Triangle Angles:

A triangle in which no interior angles are equal is called a scalene triangle.

Right-angled Triangle Angles:

A triangle in which one of the angles is equal to 90° is called a right-angled triangle.

How Many Right Angles in a Rectangle?

A rectangle is four sides closed figure.
Opposite sides of the rectangle are parallel and equal.
It has 4 interior angles.
Each interior of the rectangle is equal to 90°.
Sum of the interior angle of the rectangle is 360°.

The four-interior angle of the rectangle is ∠A, ∠B, ∠C, and ∠D.

∠A = ∠B = ∠C = ∠D = 90°

∠A + ∠B + ∠C + ∠D = 360°

Angles in a Square

A square is four sides closed figure.
Each side of the square is equal in length.
It has 4 interior angles.
Each interior of the square is equal to 90°.
Sum of the interior angle of the square is 360°.

The four-interior angles of the square are ∠A, ∠B, ∠C, and ∠D.

∠A = ∠B = ∠C = ∠D = 90°

∠A + ∠B + ∠C + ∠D = 360°

Missing Angles

Example 1:

Find the missing angle of the given triangle.

Solution:

Sum of the given angle = 120° + 28°

= 148°

The total sum of the interior angle = 180°

Missing angle = 180° – 148°

= 32°

Example 2:

Find the missing angle.

Solution:

Given angle = 60°

Total sum = 90°

Missing angle = 90° – 60°

= 30°