Answer:
The measure of the vertex angle is 94 degrees ⇒ A
Step-by-step explanation:
- In any triangle, the sum of the measures of its interior angle is 180°
- In the isosceles triangle, the two base angles are equal in measures
∵ In an isosceles triangle, the measure of the base angle = (2x + 5)
∵ The base angles of the isosceles triangles are equal in measures
∴ The measures of the base angles are (2x + 5), (2x + 5)
∵ The measure of the vertex angle = (5x - 1)
∵ The sum of the measure of the three angles = 180°
∴ (2x + 5) + (2x + 5) + (5x - 1) = 180
→ Add the like terms in the left side
∵ (2x + 2x + 5x) + (5 + 5 + -1) = 180
∴ 9x + 9 = 180
→ Subtract 9 from both sides
∴ 9x + 9 - 9 = 180 - 9
∴ 9x = 171
→ Divide both sides by 9 to find x
∴ x = 19
→ Substitute the value of x in the measure of the vertex angle to find it
∵ The measure of the vertex angle = 5x - 1
∴ The measure of the vertex angle = 5(19) - 1
∴ The measure of the vertex angle = 95 - 1
∴ The measure of the vertex angle = 94°
∴ The measure of the vertex angle is 94 degrees
The reflex angle is the other angle
see image below
so
reflex=360-angle
reflex=360-60=300
reflex angle=300
1. Height of the equilateral triangle is: √3 units
2. Area of the equilateral triangle = √3 units²
3. Area = √3/4 x², when each side is x.
<h3>What is an Equilateral Triangle?</h3>
A triangle that has all its three sides equal in length, is referred to as an equilateral triangle.
1. Given the each side measures 2 units, and h is the height, applying the Pythagorean theorem, we would have:
h = √(2² - 1²)
h = √(4 - 1)
h = √3
2. Area of the equilateral triangle = 1/2bh = 1/2(2)(√3)
Area of the equilateral triangle = √3 units²
3. If x is the side length of the equilateral triangle, we would have:
height (h) = √[x² - (x/2)²] = √[x² - x²/4] = √(3x²/4) = √3/2x
Area = 1/2bh = 1/2(x)(√3/2x) = √3/4 x²
Learn more about equilateral triangle on:
brainly.com/question/15294703
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