It is based off of the angles of the triangle and the sides.
A triangle with a right angle (90°) is a right triangle.
A triangle with an angle larger than 90° is an obtuse triangle.
A triangle with angles that are smaller than 90° is an acute triangle. ALL ANGLES MUST BE SMALLER THAN 90°...
With sides, if a triangle has two angles that equal the same length, it is an isosceles triangle.
If NO sides are of equal length, it is a scalene triangle.
And if ALL sides are equal, then it is a equilateral triangle.
Yes is equivalent because 12 x 4 is 48 and 5x5 is 25
Answer:

Step-by-step explanation:
The figure shows a right triangle.
To calculate the measure of the angle A, you can use the inverse trigonometric function arctangent:

Identify the angle
, the opposite side and the adjacent side:

Substitute into
.
The measure of the angle A is:

Rounded to the nerarest hundreth:

Answer:
40
Step-by-step explanation:
Find the other missing angle, which is supplementary to 100 first.
Supplementary angels are a sum of 180
The missing angle is 180-100 = 80
Now use that to find missing angle x
All angles in the triangle have a sum of 180
180 = 60+80+x
180-60-80=x
40 = x