To answer this item, we let x be the measure of angle Y. If we say supplement, it is understood that when we sum up the measures of the two angles (angle Y and its supplement) the answer should be 180. Therefore the other angle is 180-x. Going back to the condition given in this item, we will be able to generate an equation,
x = 3(180 - x)
The value of x from the equation is 135. Thus, m∠Y is 135°.
Perimeter = 9 + 13 + 6 = 28 m
area = 1/2 x 9 x 5.3 = 23.85 square m
Answer:

Step-by-step explanation:
The right triangle has the hypotenuse = 18
Let 'Ф' be the missing angle
we know that
cos Ф = adjacent/hypotenuse
Here,
so
cos Ф = adjacent/hypotenuse



Therefore, the missing angle is:
