diff --git a/euclid.py b/euclid.py
index da5c4aa..f174c80 100644
--- a/euclid.py
+++ b/euclid.py
@@ -2,3 +2,8 @@
 b = input("b の値を入力: ")
 
 # TODO
+while b != 0:
+        a,b = b, int(a) % int(b)
+print('最大公約数：{}'.format(a)) 
+
+    
\ No newline at end of file
diff --git a/machine_epsilon.py b/machine_epsilon.py
index f87f5c1..ff2b6a3 100644
--- a/machine_epsilon.py
+++ b/machine_epsilon.py
@@ -1 +1,5 @@
-# TODO
\ No newline at end of file
+# TODO
+epsilon = 1
+while 1 + epsilon > 1:
+    epsilon = epsilon/2
+print(epsilon)
\ No newline at end of file
diff --git a/prime_number.py b/prime_number.py
index 2308cf4..d86f33a 100644
--- a/prime_number.py
+++ b/prime_number.py
@@ -1,4 +1,19 @@
 a = input("aの値を入力: ")
 b = input("bの値を入力: ")
 
-# TODO
\ No newline at end of file
+# TODO
+for x in [a,b]:
+    if int(x) < 2:
+        print('{}は素数ではない'.format(x))
+        continue
+
+    is_prime = True
+    for i in range(2,int(x)):
+        if int(x) % i ==0:
+            is_prime = False
+            break
+    
+    if is_prime:
+        print('{}は素数'.format(x))
+    else:
+        print('{}は素数ではない'.format(x))
\ No newline at end of file
diff --git a/trapezoidal_integral.py b/trapezoidal_integral.py
index 716aa70..8d4b102 100644
--- a/trapezoidal_integral.py
+++ b/trapezoidal_integral.py
@@ -3,3 +3,23 @@
 # print(sin(0))
 # >>> 0
 # -----------
+from math import pi
+h = ( pi/2 - 0 ) / 100
+S=0
+for i in range(1,101):
+    S += h/2 * (sin(0+(i-1)*h)+ sin(0+i*h))
+print(S)
+    
+
+
+
+    
+
+
+
+
+
+
+
+
+