For an obtuse triangle, where is the altitude from one of the acute angle vertices located?

Perpendicular to an extended base line, outside the triangle

It is always one of the sides of the triangle

Which of the following statements correctly describes how the area formula $A = \frac{1}{2}bh$ is applied to different triangles?

The formula is the same, but the method for finding the height $h$ can vary.

A different formula is required for obtuse triangles.

The formula only applies to right triangles where the legs are the base and height.

The base $b$ must always be the shortest side of the triangle.

Area Practice — Grade 4 amc_math

Lesson 2: Area — Practice Questions

1. An acute triangle has a base of 14 cm and a corresponding altitude of 9 cm. What is the area of the triangle in square centimeters? ___ sq cm.
2. For an obtuse triangle, where is the altitude from one of the acute angle vertices located?
- A. Always inside the triangle
- B. Perpendicular to an extended base line, outside the triangle
- C. It is always one of the sides of the triangle
- D. It is parallel to the base
3. An obtuse triangle has a base of length 15 inches. The height drawn to the extension of this base is 6 inches. What is the area of the triangle? ___ sq in.
4. A triangle has an area of 48 square feet and a base of 12 feet. What is the length of the altitude corresponding to this base? ___ ft.
5. Which of the following statements correctly describes how the area formula $A = \frac{1}{2}bh$ is applied to different triangles?
- A. The formula is the same, but the method for finding the height $h$ can vary.
- B. A different formula is required for obtuse triangles.
- C. The formula only applies to right triangles where the legs are the base and height.
- D. The base $b$ must always be the shortest side of the triangle.
6. A composite figure is made of a $6 \times 8$ rectangle and a triangle with a base of $8$ and a height of $5$ attached to one side. What is the total area of the figure? ___
7. A large rectangular backyard is $15$ meters by $10$ meters. A rectangular vegetable garden measuring $5$ meters by $2$ meters is planted inside it. What is the area of the remaining yard? ___
8. An L-shaped polygon can be broken into two non-overlapping rectangles. Which method is best to find its total area?
- A. Add the areas of the two rectangles
- B. Subtract the area of one rectangle from the other
- C. Multiply the perimeters of the two rectangles
- D. Find the average of the two areas
9. A figure consists of a square with a side length of $7$ units and a triangle with a base of $7$ units and a height of $6$ units. Find the total area. ___
10. A rectangular piece of wood is $20$ inches by $10$ inches. A triangular corner with a base of $10$ inches and a height of $4$ inches is cut off. What is the area of the remaining piece?
- A. 180 sq. in.
- B. 200 sq. in.
- C. 20 sq. in.
- D. 220 sq. in.