Answer:
Q17) 329m²
Q15) 17,024cm²
Q14) 96
Step-by-step explanation:
Q17)
Find the surface area of the triangle.
The formula to finding the area of a triangle is (b×h)÷2.
The base and height is given, 7m and 5m, respectively. This makes the formula into (7×5)÷2.
Simplyifying it, it turns into 35÷2 which equals 17.5m². Since there are two triangles, the total area of the triangles is 35m².
Now you need to find the area of each of the rectangles. The formula to finding the area of rectangles is simply b×h.
For the rectangle thats in view, the formula will be 14×6 which equals 84cm².
For the rectangle thats at the bottom, you can tell by the base of the triangle and the length of the first trectangle, that the base is 14m and the height is 7m, making the formula 14×7 which equals 98m².
For the last rectangle, you can tell by the base of the first rectangle and one of the sides of the traingle that the base is 14m and the height is 8m, making the formula 14×8 which equals 112m².
To find the total surface area, you need to add all the answers we came up with (all the answers in bold) together. 35m² + 84m² + 98m² + 112m² = 329m².
Q15)
If you rotate the shape anti-clockwise, you can see that the shape is a trapezium. The formula for finding the area of a trapezium is {(a+b)×h}÷2. (Basically, adding A and B together, mutiplying the answer by the height and dividing the whole result by two.)
A and B in a trapezium are the top and bottom lines, which are 80cm and 186cm. The height in the trapezium is shown by the dotted line, which is 128cm. Substituting the letters for the numbers in this problem, you get:
{(80+186)×128}÷2.
To solve it, we first need to add 80 and 186, which adds up to 266.
Now the formula is (266×128)÷2.
If we multiply 266 by 128, we get 34,048.
The formula is now 34,048÷2. Solving this, we get 17,024.
Therefore, the answer is 17,024cm².
Q14)
This question is rather simple to solve. There are 6 equal squares, and each square is 4 units in length and 4 units in width (because it's a square, both length and width is equal).
4×4 = 16. This means that each square is 16 units. Since there are 6 equal squares and each square is 16 units, you can easily multiply 6 by 16, to get 96. Making the answer 96.
