I can find the area of a triangle using the formula A = ½ × base × height.Puedo hallar el área de un triángulo usando la fórmula A = ½ × base × altura.
MissionMisión · Harbor WorksPuerto de trabajo
Keep the port running.Mantén el puerto en marcha.
Harbor Works is busy. Sails, signal flags and warning pennants are all triangles, and the crew must know the area of each one to order cloth. Use the base and the perpendicular height to keep the port running.
Las Obras del Puerto están muy ocupadas. Las velas, las banderas de señales y las banderolas de aviso son triángulos, y el equipo debe conocer el área de cada uno para pedir tela. Usa la base y la altura perpendicular para que el puerto siga funcionando.
Word bankBanco de palabras 4 words4 palabrastriangle, base, height, …triángulo, base, altura, …
- triangletriángulo
- A shape with three sides. Its area is half of a rectangle with the same base and height.Una figura con tres lados. Su área es la mitad de un rectángulo con la misma base y altura.
- basebase
- Any side of a triangle. The height is measured perpendicular to it.Cualquier lado de un triángulo. La altura se mide perpendicular a ella.
- heightaltura
- The straight distance from the base to the opposite corner, at a right angle to the base.La distancia recta desde la base hasta la esquina opuesta, en ángulo recto con la base.
- perpendicularperpendicular
- Meeting to make a square corner of 90 degrees.Que se cruza formando una esquina cuadrada de 90 grados.
Stage 1 of 5Etapa 1 de 5
Get ReadyPrepárate
Wake up what you know, then explore today's model.
Activa lo que sabes y luego explora el modelo de hoy.
- A triangle has a base of 10. Predict what happens to its area when the height doubles from 3 to 6. Predict on paper, then test both heights in the model and use the two triangle area numbers as evidence. Explain why.
- What is the area of a rectangle 8 cm long and 5 cm wide?
- 13 square cm
- 26 square cm
- 40 square cm
- 40 cubic cm
- What is the area of a parallelogram with base 9 in and height 4 in?
- 13 square in
- 18 square in
- 26 square in
- 36 square in
- In a parallelogram, how is the height measured?
- Along the slanted side
- Perpendicular to the base
- Around the outside
- From one corner to the opposite corner
- 1 fresh problem with new numbers each time (interactive only).
Stage 2 of 5Etapa 2 de 5
Try ItInténtalo
Use the hints when you need them. Every wrong answer tells you why.
Usa las pistas cuando las necesites. Cada respuesta incorrecta te dice por qué.
- What is the area of a triangle with base 10 cm and height 6 cm?
- 16 sq cm
- 30 sq cm
- 30 cm
- 60 sq cm
- A triangular garden bed in the firm's park design has an area of 24 sq ft and a base of 8 ft. What is the height?
- 3 ft
- 6 ft
- 12 ft
- 16 ft
- Why do we divide by 2 when finding the area of a triangle?
- A triangle is exactly half of a rectangle with the same base and height
- Triangles have 2 equal sides
- The base is always twice the height
- We always divide area formulas by 2
Stage 3 of 5Etapa 3 de 5
On Your OwnPor tu cuenta
Tables, mistakes to find, and problems with a few steps.
Tablas, errores por encontrar y problemas de varios pasos.
- Fill in the table
- Match each shape to its area. Watch the rule: triangles use A = ½ × base × height, but parallelograms and rectangles use A = base × height (do NOT take half).
- A triangle has a base of 10 ft and an area of 35 sq ft. Place a point at the height. (Hint: 35 = ½ × 10 × h → 35 = 5h → h = 7)
- What is the best next move?
- Write 112 cm² as the area of the triangle.
- Divide 112 by 7 to get back to the base.
- Double 112.
- Take half of 112.
Stage 4 of 5Etapa 4 de 5 · OptionalOpcional
Practice MorePractica más
Optional extra practice. Press New numbers for another problem on the same skill.
Práctica extra opcional. Toca Números nuevos para otro problema de la misma habilidad.
- 5 fresh problems with new numbers each time (interactive only).
Stage 5 of 5Etapa 5 de 5
Show What You KnowDemuestra lo que sabes
Show what you learned today. Take your time; you can try again.
Muestra lo que aprendiste hoy. Tómate tu tiempo; puedes intentarlo otra vez.
- What is the area of the triangular wall?
- 34 sq ft
- 70 sq ft
- 140 sq ft
- 280 sq ft
- How many cans of paint does she need?
- 2
- 2.8
- 3
- 4
- Why round up instead of down?
- Because 2 cans cover only 100 sq ft, which is not enough for 140
- Because paint is always sold in threes
- Because 2.8 rounds to 3 by the usual rule
- Because the wall might be bigger