# Lesson 9

Formula for the Area of a Triangle

### Problem 1

Select all drawings in which a corresponding height $$h$$ for a given base $$b$$ is correctly identified.

A:

A

B:

B

C:

C

D:

D

E:

E

F:

F

### Solution

For access, consult one of our IM Certified Partners.

### Problem 2

For each triangle, a base and its corresponding height are labeled.

1. Find the area of each triangle.
2. How is the area related to the base and its corresponding height?

### Solution

For access, consult one of our IM Certified Partners.

### Problem 3

Here is a right triangle. Name a corresponding height for each base.

1. Side $$d$$
2. Side $$e$$
3. Side $$f$$

### Solution

For access, consult one of our IM Certified Partners.

### Solution

For access, consult one of our IM Certified Partners.

(From Unit 1, Lesson 8.)

### Problem 5

Andre drew a line connecting two opposite corners of a parallelogram. Select all true statements about the triangles created by the line Andre drew.

A:

Each triangle has two sides that are 3 units long.

B:

Each triangle has a side that is the same length as the diagonal line.

C:

Each triangle has one side that is 3 units long.

D:

When one triangle is placed on top of the other and their sides are aligned, we will see that one triangle is larger than the other.

E:

The two triangles have the same area as each other.

### Solution

For access, consult one of our IM Certified Partners.

(From Unit 1, Lesson 7.)

### Problem 6

Here is an octagon. (Note: The diagonal sides of the octagon are not 4 inches long.)