For each group of three forces below, determine whether the forces in each pair are pulling at right angles to each other.

a. 12 lb, 13 lb, resultant force 19 lb, yes; 15 lb, 36 lb, resultant force 39 lb, yes

b. 12 lb, 13 lb, resultant force 19 lb, no; 15 lb, 36 lb, resultant force 39 lb, yes

c. 12 lb, 13 lb, resultant force 19 lb, yes; 15 lb, 36 lb, resultant force 39 lb, no

d. 12 lb, 13 lb, resultant force 19 lb, no; 15 lb, 36 lb, resultant force 39 lb, no

Arunning track in the shape of an oval is shown. the ends of the track form semicircles. a running track is shown. the left and right edges of the track are identical curves. the top and bottom edges of the track are straight lines. the track has width 56 m and length of one straight edge 130 m. what is the perimeter of the inside of the track? (π = 3.14) 260.00 m 347.92 m 372.00 m 435.84 m

I'm terrible at math any here is appreciated.

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.