The given triangle is a right triangle.
The tangent of an angle of right triangle is obtained by dividing the opposite side of the angle with the adjacent side of the angle.
The opposite side of angle R is 5 cm and the adjacent side of angle R is 12 cm.
tan R = 5 / 12 = 0.4167
R = arctan (0.4167) = 22.6 degrees.
You would first make the fractions improper (making the numerator bigger then the denominator) in order to do that times the denominator with the whole number and add the numerator.
Ex) 3*8 = 24 + 5 = 29/8
Then you would add both of the improper fractions
45 handshakes are possible
Ok so cos(x) = sin(90-x) so using that you can get sin(7x-15) = sin(90-(3x+5)) so 7x-15 = -3x+85. 10x = 100 and x = 10. Use that to find the 2 angles are 55 and 35
You can do
3 * 2 and 11 * 2 which would be 6:22 and is still equal to the ratio 3:11. Your explanation can be the when divided by 2 or the number you multiplied by, you would get the original ratio
Examples:
6:22
9:33
12:44