Question

The measure of two angles of
a triangle are 45°
and 36°
Find the measure of third angle​

Answer 1

Step-by-step explanation:

Given :

first angle of triangle = 45°

second angle of triangle = 36°

Theorem :

According to angle sum property,

the sum of angles of any triangle is 180°

Solution :

let's take the third unknown angle be x

45° + 36° + x = 180°

81° + x = 180°

x = 180° - 81°

x = 99°

The third angle of triangle is 99°

Answer 2

★Given :

• Measure of the first angle = 45°
• Measure of the second angle = 36°

★ To Find :

• Measure of the third angle.

❇ Solution :

Let the third angle be x°.

• $\bigstar\boxed {\bf{Sum \:of \:all\: angles = 180^{\circ}}}$

$\implies \sf {45^{ \circ}} + 36^{ \circ} + x^{ \circ} = 180^{ \circ}$

$\implies \sf {81^{ \circ}} + x^{ \circ} = 180^{ \circ}$

$\implies \sf x^{ \circ} = {(180 - 81)}^{ \circ}$

$\implies \underline { \boxed{\bf x^{ \circ} = 99^{ \circ}}}$

Hence, the third angle is 99°.

Extra information :

• Triangle having 3 vertices, 3 angles , 3 sides.

• It's a 2D figure.

• Classification according to angles : Right angled triangle , Acute angled triangle , Obtuse angled triangle.

• Classification according to sides : Equilateral triangle, Isosceles triangle , Scalene triangle.