Question

The net of a triangular prism is shown. a) Work out the length x. b) Work out the area of the shaded face. 3 cm 7 cm 5 cm 8 9 cm Not drawn accurately​

Answer 1

a. The length of the side x is 5cm

b. The area of the shaded face is 49cm²

To determine the value of the variable x, we have to know that given an acute angle in a right triangle, the adjacent side is the leg of the triangle from which the angle to the hypotenuse is measured.

So, we can see that the side length of the top of the largest rectangle is adjacent in length to the value of x, then, we have that;

x = 5cm

Since, the formula for area of a rectangle is;

Area = length ×width

Substitute the values

Area = 9 × 5

Multiply the values

Area = 45cm²