Since, 8 and 5 both are prime numbers u can simply multiply 8 and 15 to get your answer..
the ans is 120..
Step 1: Convert
, which is in radians into degrees. To convert it multiply by 

900/12
75
Step 2: 75 degrees isn't on the unit circle but 45 degrees and 30 degrees is. Since 45 + 30 = 75 you can use the cosine of 45 and 30 to find the exact value
cos45 = 
cos30 =
Step 3: Add the cos45 and cos30 to get cos5pi/12

Hope this helped!
Answer:
Step-by-step explanation:
Area inside the semi-circle and outside the triangle is (91.125π - 120) in²
Solution:
Base of the triangle = 10 in
Height of the triangle = 24 in
Area of the triangle = 

Area of the triangle = 120 in²
Using Pythagoras theorem,




Taking square root on both sides, we get
Hypotenuse = 23 inch = diameter
Radius = 23 ÷ 2 = 11.5 in
Area of the semi-circle = 

Area of the semi-circle = 91.125π in²
Area of the shaded portion = (91.125π - 120) in²
Area inside the semi-circle and outside the triangle is (91.125π - 120) in².