AccelePrep for the ACT Test 2nd Edition Student Text

114 • S URGE TO S UCCESS ! M ATH T EST P REP

4. Š‡…Š‘”† ‹ –Š‡ ϐ‹‰—”‡ „‡Ž‘™ ‹• ͳ͸ —‹–• Ž‘‰ ƒ† ͸ —‹–• ˆ”‘ –Š‡ center of circle O . What is the radius of circle O ?

REVIEW In a right triangle, the square of the longest side (the hypotenuse) is equal to the sum of the squares of the other two sides (the legs):

O r 6 16

F. 5 G. 10 H. 12 Ǥ ͳͶ Ǥ ͳͲɎ

c

b

a

a b c 2 2 2

‡”‡ǯ• ƒ ’”‘„Ž‡ –Šƒ– Ž‘‘• ˜‡”› †‹ˆϐ‹…—Ž– „—– „‡…‘‡• ‡ƒ•› ™Š‡ ›‘— measure. 5. Š‡ ϐ‹‰—”‡ „‡Ž‘™ •Š‘™• –Š‡ •–”—…–—”ƒŽ ‡Ž‡‡–• ‘ˆ ƒ „ƒ”Ǥ Šƒ– ‹• –Š‡ †‹•–ƒ…‡ǡ ‹ ˆ‡‡–ǡ ˆ”‘ –Š‡ ϐŽ‘‘” ‘ˆ –Š‡ „ƒ” –‘ –Š‡ ’‡ƒ ‘ˆ –Š‡ ”‘‘ˆǫ

Example:

60 ° 45 ° 45 °

A REVIEW 45°-45°-90° triangles are right isosceles triangles with a hypotenuse equal to the length of either side multiplied by 2 . In a 30°-60°-90° triangle, the leg opposite the 30° angle equals the hypotenuse length multiplied by 2 1 ; the leg opposite the 60° angle equals the hypotenuse length multiplied by 2 3 . B 45 ° 45 ° x x C x 2

30 °

x °

45 °

45 °

9 ft

9 ft

12 ft

18 ft

A. 6.75 B. 12 C. 18.75 D. 18 2 3 3 E. 12 9 2

x 60 °

30 °

2 x 1

3 3

2

3

x

2