Question

I am having trouble with this question, can anyone help? This is for Geometry.

Answer 1

by geometry rules

for a triangle

external angle of a triangle is equal to the sum of two internal angle of the triangle ( other than external adjacent angle)

m<1= sum of m<2 and m<3

m<1= m<1+<2

m<1 = 31+72

m<1= 103

hope you are clear now !

Answer 2

The correct answer is last option. 103

Explanation:

Points to remember

Sum of any two angles of a triangle is equal to the exterior angle of the third angle

To find the measure of <1

It is given that m<2 = 31° and m< 3 = 72°

From the figure we can see that <2 and <3 are two angles of a triangle. And <1 is the exterior angle of third angle of same triangle.

Therefore we can write,

m<2 + m<3 = m<1

m<1 = 31 + 72

= 103°

Therefore the correct answer is last option. 103