Question

question 13

1. find the value for x given the follow gram.

a) 46 b) 23 c) 49 d) 80
80
49
46
23
(the image shows a triangle with an exterior angle of 100°, one interior angle of (2x + 3)°, and another interior angle of 51°)

Explanation:

Step1: Use exterior angle theorem

The exterior angle of a triangle equals the sum of the two non - adjacent interior angles. So, \(100^{\circ}=(2x + 3)^{\circ}+51^{\circ}\)

Step2: Solve for x

First, subtract \(51^{\circ}\) from both sides: \(100 - 51=2x + 3\)
\(49 = 2x+3\)
Then, subtract 3 from both sides: \(49 - 3=2x\)
\(46 = 2x\)
Finally, divide both sides by 2: \(x=\frac{46}{2}=23\)

Answer:

d) 23