Two year 9 maths questions

[Oxform]

Hi, I'm in year 9 and have been given two questions which I don't seem to understand.

The edges of a square are √2k cm. What is the length of the diagonal of the square.

and...

A solid cone has radius of 12cm and a surface area of 336π cm^2

The surface area (S) of a solid cone is given by the formula:
S=πr^2+πrL

Where L is the slant height of the cone and r is the radius.
1) Show that the slant height of the cone is 16cm.

Thank you

 

[Deleted member 4993]

Hi, I'm in year 9 and have been given two questions which I don't seem to understand.

The edges of a square are √2k cm. What is the length of the diagonal of the square.

and...

A solid cone has radius of 12cm and a surface area of 336π cm^2

The surface area (S) of a solid cone is given by the formula:
S=πr^2+πrL

Where L is the slant height of the cone and r is the radius.
1) Show that the slant height of the cone is 16cm.

Thank you

Hint: from the given equation:

S=πr^2+πrL

Isolate L and solve for it. What are your thoughts?

Please share your work with us ...even if you know it is wrong

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[stapel]

1. The edges of a square are √2k cm. What is the length of the diagonal of the square.

Draw a square. Label the sides with, say, a length of "1". Draw a diagonal. This forms a right triangle. Use the Pythagorean Theorem to find the length of the diagonal. Note the relationship between this length and the lengths of the sides.

If you're not sure of the relationship, repeat the process with a square with sides of length 2, then of length 3, and so forth. Once you see the pattern, consider the given square.

2. A solid cone has radius of 12cm and a surface area of 336π cm^2

The surface area (S) of a solid cone is given by the formula S=πr^2+πrL, where L is the slant height of the cone and r is the radius. Show that the slant height of the cone is 16cm.

You are given a formula containing slots (variable) for the values of the surface area, the radius, and the slant height. You are given the values of the surface area and the radius. You are asked for the value of the remaining slot (variable).

Plug the given numbers into the given formula. Solve for the specified (and only remaining) variable.