CHAPTER 10 / ESSENTIAL GEOMETRY SKILLS 377
- 36 Sketch a diagram. Point Khas coordinates
(11, 1). ∆HJKis a right triangle, so it satisfies the
Pythagorean theorem. Your diagram should look
like this one. The perimeter is 9 + 12 + 15 =36.
7. 324 Since the garden is a
square, the diagonal divides it
into 45°-45°-90° triangles.
Therefore the sides have a
length of 24. The outer edge of
the walkway is therefore
24 + 3 + 3 =30. The area of the
walkway is the difference of
the areas of the squares:
302 − 242 =324.
8. B The sum of the angles is 180°, so x+x+ 2 x=
4 x=180, and x=45. Therefore the triangle is a
45 °-45°-90°triangle. Since it is isosceles, 3y= 2 y+5,
and therefore y=5. The three sides, then, have
lengths of 15, 15, and 15 2.
24
2
3
30
24
H(2, 1)J(11, 13)K(11, 1)
xy12915