Question

what is the surface area of this triangular prism? 25 cm 20 cm 25 cm 30 cm 7 cm square centimeters submit work it out not feeling ready yet? these can help: area of triangles surface area of cube

Explanation:

Step1: Calculate area of triangular bases

The area formula for a triangle is $A=\frac{1}{2}bh$. Here, $b = 30$ cm and $h=20$ cm. So, $A_{triangle}=\frac{1}{2}\times30\times20= 300$ $cm^{2}$. Since there are 2 triangular bases, the total area of the bases is $2\times300 = 600$ $cm^{2}$.

Step2: Calculate area of rectangular faces

There are 3 rectangular faces.

• For the first rectangular face with dimensions 25 cm and 7 cm, $A_1=25\times7 = 175$ $cm^{2}$.
• For the second rectangular face with dimensions 25 cm and 7 cm, $A_2=25\times7 = 175$ $cm^{2}$.
• For the third rectangular face with dimensions 30 cm and 7 cm, $A_3=30\times7=210$ $cm^{2}$.

The total area of the rectangular faces is $A_{rectangles}=175 + 175+210=560$ $cm^{2}$.

Step3: Calculate total surface - area

The surface area of the triangular prism $A = A_{bases}+A_{rectangles}$. So, $A=600 + 560=1160$ $cm^{2}$.

Answer:

1160