Find the measure of ∠A in Fig. 6.36.
Solution:
Given, ABC is a triangle
We have to find the measure of ∠A.
Exterior angles are defined as the angles formed between the side of the polygon and the extended adjacent side of the polygon.
From the figure,
The exterior angle is 115°.
The exterior angle theorem states that the measure of an exterior angle is equal to the sum of the measures of the two opposite interior angles of the triangle.
The interior angles are ∠BAC and ∠ABC.
By the exterior angle property,
115° = ∠BAC + ∠ABC
115° = ∠BAC + 65°
∠BAC = 115° - 65°
∠BAC = 50°
Therefore, ∠A is 50°.
✦ Try This: Find the value of x and y in fig.
☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 6
NCERT Exemplar Class 7 Maths Chapter 6 Problem 119
Find the measure of ∠A in Fig. 6.36.
Summary:
The measure of ∠A in Fig. 6.36 is 50°.
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