Geometry

A right triangle has legs of length $6$ and $8$. Find the length of the hypotenuse.

Sir Reginald the Squirrel is stuck at the bottom of a giant oak tree, clutching an acorn the size of his own head. His nut-stash is up in a hollow that is $12$ meters straight up the trunk. But Sir Reginald refuses to climb straight up (too mainstream), so he takes his patented 'Diagonal Dash' along a perfectly straight ramp. The base of the ramp starts $5$ meters away from the trunk on the ground. If the ground, the trunk, and the ramp form a right triangle, how long is Sir Reginald's diagonal ramp $c$ (in meters)?

A right triangle has legs measuring $9$ units and $12$ units. Find the length of the hypotenuse.

A rectangle has a length of $15$ meters and a width of $8$ meters. Find its area in square meters.

A rectangle has a length of $12$ cm and a width of $7$ cm. Find the perimeter of the rectangle.