diff --git a/education/software development/ECE1400/Chapter 9 Exercises.md b/education/software development/ECE1400/Chapter 9 Exercises.md
index 12cd8df..008bcdf 100644
--- a/education/software development/ECE1400/Chapter 9 Exercises.md	
+++ b/education/software development/ECE1400/Chapter 9 Exercises.md	
@@ -1,4 +1,28 @@
 > 1. The following function, which computes the area of a triangle, contains two errors. Locate the errors and show how to fix them. (*Hint*: There are no errors in the formula)
 ```c
+double triangle_area(double base, height)
+double product;
+{
+	product = base * height;
+	return product / 2;
+}
+```
 
+Answer:
+```c
+// A type annotation is needed for `height`
+double triangle_area(double base, double height)
+{
+	// The `product` variable declaration was not in the function block.
+	double product;
+	product = base * height;
+	return product / 2;
+}
+```
+
+> 2. Write a function `check(x, y, n)` that returns `1` if both `x` and `y` fall between zero and `n - 1` inclusive. The function should return 0 otherwise. Assume that `x`, `y`, and `n` are all of type int
+```c
+int check(int x, int y, int n) {
+	if (x < 0)
+}
 ```
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