Question

Can somebody help me with the Math's questions on Pythagoras Theorem? Thanks

Answer 1

Answer:

2.4 cans cost 47.4

If you cannot buy 2.4 cans, you must buy 3 cans, then you'll pay 59.25

Step-by-step explanation:

The lawn has trapezoidal shape, so find the area of the trapezoid using formula

$A=\text{Midline}\times \text{Height}$

In the diagram, ABED is rectangle, so BE = 12 m, thus ED = 20 m - 12 m = 8 m.

Consider right triangle EDC. By the Pythagorean theorem,

$ED^2+EC^2=CD^2\\ \\ED^2+8^2=17^2\\ \\ED^2=289-64\\ \\ED^2=225\\ \\ED=15\ m$

Thue,

Height = 15 m

Find the midline:

$\text{Midline}=\dfrac{AD+BC}{2}=\dfrac{12+20}{2}=16\ m$

Hence,

$A=16\cdot 15=240\ m^2$

One can cover $100\ m^2,$ to cover $240\ m^2$ is needed

$240:100=2.4$ cans

One can costs 19.75, so 2.4 cans cost

$19.75\cdot 2.4=47.4$

If you cannot buy 2.4 cans, you must buy 3 cans, then you'll pay

$19.75\cdot 3=59.25$